Cisco IOS IP Configuration Guide Release 12.2 Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.
THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS.
CONTENTS About Cisco IOS Software Documentation Documentation Objectives Audience xxix xxix xxix Documentation Organization xxix Documentation Modules xxix Master Indexes xxxii Supporting Documents and Resources New and Changed Information Document Conventions xxxii xxxiii xxxiii Obtaining Documentation xxxv World Wide Web xxxv Documentation CD-ROM xxxv Ordering Documentation xxxv Documentation Feedback xxxv Obtaining Technical Assistance xxxvi Cisco.
Contents Determining a Routing Process IPC-2 Interior and Exterior Gateway Protocols IPC-2 Interior Gateway Protocols IPC-3 Exterior Gateway Protocols IPC-3 Multiple Routing Protocols IPC-3 IP Multicast IPC-4 IP ADDRESSING AND SERVICES Configuring IP Addressing IP Addressing Task List IPC-7 IPC-7 Assigning IP Addresses to Network Interfaces IPC-7 Assigning Multiple IP Addresses to Network Interfaces Enabling Use of Subnet Zero IPC-9 Disabling Classless Routing Behavior IPC-10 Enabling IP Processing on
Contents Suppressing Forward and Reverse Record Options IPC-26 Specifying the NHRP Responder Address IPC-26 Changing the Time Period NBMA Addresses Are Advertised as Valid Configuring a GRE Tunnel for Multipoint Operation IPC-27 Configuring NHRP Server-Only Mode IPC-27 Enabling IP Routing IPC-27 Routing Assistance When IP Routing Is Disabled Proxy ARP IPC-28 Default Gateway IPC-28 ICMP Router Discovery Protocol IPC-29 Enabling IP Bridging IPC-26 IPC-28 IPC-30 Enabling Integrated Routing and Bridging Co
Contents Displaying System and Network Statistics IPC-48 Monitoring and Maintaining NHRP IPC-49 IP Addressing Examples IPC-49 Creating a Network from Separated Subnets Example IPC-50 Serial Interfaces Configuration Example IPC-50 IP Domains Example IPC-51 Dynamic Lookup Example IPC-51 HP Hosts on a Network Segment Example IPC-51 Logical NBMA Example IPC-51 NHRP over ATM Example IPC-53 Changing the Rate for Triggering SVCs Example IPC-55 Applying NHRP Rates to Specific Destinations Example IPC-57 NHRP on a
Contents Configuring the Address Lease Time IPC-71 Configuring Manual Bindings IPC-71 Configuring a DHCP Server Boot File IPC-73 Configuring the Number of Ping Packets IPC-73 Configuring the Timeout Value for Ping Packets IPC-73 Enabling the Cisco IOS DHCP Client on Ethernet Interfaces IPC-73 Configuring DHCP Server Options Import and Autoconfiguration IPC-74 Configuring the Relay Agent Information Option in BOOTREPLY Messages Configuring a Relay Agent Information Reforwarding Policy IPC-75 Enabling the DH
Contents Applying Time Ranges to Access Lists IPC-97 Including Comments About Entries in Access Lists IPC-98 Applying Access Lists IPC-98 Controlling Access to a Line or Interface IPC-99 Controlling Policy Routing and the Filtering of Routing Information Controlling Dialer Functions IPC-99 IPC-99 Configuring the Hot Standby Router Protocol IPC-100 Enabling HSRP IPC-101 Configuring HSRP Group Attributes IPC-102 Changing the HSRP MAC Refresh Interval IPC-102 Enabling HSRP MIB Traps IPC-103 Enabling HSRP Su
Contents Enabling CEF IPC-116 Enabling NetFlow Switching IPC-117 Enabling IP Multicast Routing IPC-117 Configuring the Router as a Forwarding Agent IPC-118 Monitoring and Maintaining the IP Network IPC-118 Clearing Caches, Tables, and Databases IPC-118 Monitoring and Maintaining the DRP Server Agent IPC-119 Clearing the Access List Counters IPC-119 Displaying System and Network Statistics IPC-119 Monitoring the MNLB Forwarding Agent IPC-120 Monitoring and Maintaining HSRP Support for ICMP Redirect Messag
Contents Port-Bound Servers IPC-136 Client-Assigned Load Balancing IPC-136 Content Flow Monitor Support IPC-136 Sticky Connections IPC-136 Maximum Connections IPC-136 Delayed Removal of TCP Connection Context IPC-137 TCP Session Reassignment IPC-137 Automatic Server Failure Detection IPC-137 Automatic Unfail IPC-137 Slow Start IPC-137 SynGuard IPC-137 Dynamic Feedback Protocol for IOS SLB IPC-138 Alternate IP Addresses IPC-138 Transparent Web Cache Balancing IPC-138 NAT IPC-138 Redundancy Enhancement—State
Contents Verifying Server Failure Detection Troubleshooting IOS SLB IPC-150 Monitoring and Maintaining IOS SLB IPC-149 IPC-151 Configuration Examples IPC-151 IOS SLB Network Configuration Example IPC-152 NAT Configuration Example IPC-153 HSRP Configuration Example IPC-155 IOS SLB Stateless Backup Configuration Example IPC-157 Configuring Mobile IP IPC-159 Mobile IP Overview IPC-159 Why is Mobile IP Needed? IPC-159 Mobile IP Components IPC-160 How Mobile IP Works IPC-161 Agent Discovery IPC-161 Registr
Contents Enabling HSRP IPC-171 Configuring HSRP Group Attributes IPC-171 Enabling HA Redundancy for a Physical Network IPC-172 Enabling HA Redundancy for a Virtual Network Using One Physical Network IPC-172 Enabling HA Redundancy for a Virtual Network Using Multiple Physical Networks IPC-173 Enabling HA Redundancy for Multiple Virtual Networks Using One Physical Network IPC-174 Enabling HA Redundancy for Multiple Virtual Networks Using Multiple Physical Networks IPC-174 Verifying HA Redundancy IPC-175 Moni
Contents Restrictions to RIP Route Summarization IPC-205 Configuring Route Summarization on an Interface IPC-205 Verifying IP Route Summarization IPC-205 Disabling Automatic Route Summarization IPC-206 Running IGRP and RIP Concurrently IPC-206 Disabling the Validation of Source IP Addresses IPC-207 Enabling or Disabling Split Horizon IPC-207 Configuring Interpacket Delay IPC-208 Connecting RIP to a WAN IPC-208 RIP Configuration Examples IPC-209 Route Summarization Examples IPC-209 Example 1: Correct Config
Contents Enabling OSPF IPC-225 Configuring OSPF Interface Parameters IPC-225 Configuring OSPF over Different Physical Networks IPC-226 Configuring Your OSPF Network Type IPC-226 Configuring Point-to-Multipoint, Broadcast Networks IPC-227 Configuring OSPF for Nonbroadcast Networks IPC-227 Configuring OSPF Area Parameters IPC-228 Configuring OSPF NSSA IPC-229 Implementation Considerations IPC-230 Configuring Route Summarization Between OSPF Areas IPC-230 Configuring Route Summarization When Redistr
Contents Basic OSPF Configuration Example for Internal Router, ABR, and ASBRs Complex Internal Router, ABR, and ASBRs Example IPC-246 Complex OSPF Configuration for ABR Examples IPC-249 Route Map Examples IPC-250 Changing OSPF Administrative Distance Example IPC-252 OSPF over On-Demand Routing Example IPC-253 LSA Group Pacing Example IPC-255 Block LSA Flooding Example IPC-255 Ignore MOSPF LSA Packets Example IPC-255 Configuring EIGRP IPC-246 IPC-257 The Cisco EIGRP Implementation IPC-257 EIGRP Configu
Contents Configuring Integrated IS-IS IPC-277 IS-IS Configuration Task List IPC-277 Enabling IS-IS and Assigning Areas IPC-277 Enabling IP Routing for an Area on an Interface IPC-279 IS-IS Interface Parameters Configuration Task List IPC-279 Configuring IS-IS Link-State Metrics IPC-280 Setting the Advertised Hello Interval IPC-280 Setting the Advertised CSNP Interval IPC-280 Setting the Retransmission Interval IPC-281 Setting the LSP Transmissions Interval IPC-281 Setting the Retransmission Throttle In
Contents How BGP Selects Paths IPC-294 BGP Multipath Support IPC-295 Basic BGP Configuration Task List IPC-295 Advanced BGP Configuration Task List IPC-296 Configuring Basic BGP Features IPC-297 Enabling BGP Routing IPC-297 Configuring BGP Neighbors IPC-297 Managing Routing Policy Changes IPC-298 Resetting a Router Using BGP Dynamic Inbound Soft Reset IPC-299 Resetting a Router Using BGP Outbound Soft Reset IPC-300 Configuring BGP Soft Reset Using Stored Routing Policy Information IPC-300 Verifying BGP
Contents BGP Conditional Advertisement Configuration Task List IPC-315 Conditional Advertisement of a Set of Routes IPC-315 Verifying BGP Conditional Advertisement IPC-315 BGP Conditional Advertisement Troubleshooting Tips IPC-316 Configuring a Routing Domain Confederation IPC-316 Configuring a Route Reflector IPC-317 Configuring BGP Peer Groups IPC-320 Creating the Peer Group IPC-320 Assigning Options to the Peer Group IPC-321 Making Neighbors Members of the Peer Group IPC-324 Disabling a Peer or Peer Gro
Contents Inbound Soft Reset Using Stored Information Example IPC-339 BGP Synchronization Examples IPC-340 BGP Path Filtering by Neighbor Examples IPC-340 BGP Aggregate Route Examples IPC-341 BGP Community with Route Maps Examples IPC-341 BGP Conditional Advertisement Configuration Examples IPC-343 BGP Confederation Examples IPC-344 BGP Peer Group Examples IPC-345 iBGP Peer Group Example IPC-345 eBGP Peer Group Example IPC-345 TCP MD5 Authentication for BGP Examples IPC-346 Configuring Multiprotocol BGP Ext
Contents Specifying a Default Network IPC-365 Understanding Gateway of Last Resort IPC-366 Changing the Maximum Number of Paths IPC-366 Configuring Multi-Interface Load Splitting IPC-366 Redistributing Routing Information IPC-367 Understanding Supported Metric Translations IPC-369 Filtering Routing Information IPC-370 Preventing Routing Updates Through an Interface IPC-370 Configuring Default Passive Interfaces IPC-371 Controlling the Advertising of Routes in Routing Updates IPC-372 Controlling the P
Contents Default Passive Interface Example Policy Routing Example IPC-393 Key Management Examples IPC-394 IPC-393 IP MULTICAST Configuring IP Multicast Routing IPC-399 The Cisco IP Multicast Routing Implementation IGMP IPC-400 IGMP Versions IPC-401 PIM IPC-401 CGMP IPC-402 Basic IP Multicast Routing Configuration Task List IPC-400 IPC-402 Advanced IP Multicast Routing Configuration Task List Enabling IP Multicast Routing IPC-402 IPC-403 Enabling PIM on an Interface IPC-403 Enabling Dense Mode IPC
Contents Restrictions IPC-412 Changing the IGMP Query Timeout IPC-413 Changing the Maximum Query Response Time IPC-413 Configuring the Router as a Statically Connected Member Configuring IGMP Leave Latency IPC-414 Configuring the TTL Threshold IPC-413 IPC-415 Disabling Fast Switching of IP Multicast IPC-415 SAP Listener Support Configuration Task List IPC-415 Enabling SAP Listener Support IPC-415 Limiting How Long a SAP Cache Entry Exists IPC-416 Enabling the Functional Address for IP Multicast over T
Contents Controlling the Transmission Rate to a Multicast Group IPC-430 Configuring RTP Header Compression IPC-430 Enabling RTP Header Compression on a Serial Interface IPC-432 Enabling RTP Header Compression with Frame Relay Encapsulation IPC-432 Changing the Number of Header Compression Connections IPC-432 Enabling Express RTP Header Compression IPC-433 Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits IPC-434 Enabling IP Multicast over ATM Point-to-Multipoint VCs IPC-436 Limiting
Contents Express RTP Header Compression with Frame Relay Encapsulation Example IP Multicast over ATM Point-to-Multipoint VC Example IPC-454 Administratively Scoped Boundary Example IPC-455 IP Multicast Helper Example IPC-455 Stub IP Multicast Example IPC-456 Load Splitting IP Multicast Traffic Across Equal-Cost Paths Example IPC-457 IP Multicast Heartbeat Example IPC-458 Configuring Source Specific Multicast SSM Components Overview IPC-459 IPC-459 How SSM Differs from Internet Standard Multicast SSM IP
Contents DF Election IPC-473 Bidirectional Group Tree Building Packet Forwarding IPC-474 IPC-474 Bidir-PIM Configuration Task List IPC-474 Prerequisites IPC-474 Configuring Bidir-PIM IPC-475 Verifying Bidirectional Groups IPC-475 Monitoring and Maintaining Bidir-PIM IPC-476 Bidir-PIM Configuration Example IPC-476 Configuring Multicast Source Discovery Protocol How MSDP Works Benefits IPC-477 IPC-477 IPC-479 Prerequisites IPC-479 MSDP Configuration Task List IPC-479 Configuring an MSDP Peer IPC-48
Contents Enabling PGM Host IPC-495 Enabling PGM Host with a Virtual Host Interface IPC-496 Enabling PGM Host with a Physical Interface IPC-496 Verifying PGM Host Configuration IPC-496 PGM Router Assist Configuration Task List IPC-498 Prerequisites IPC-498 Enabling PGM Router Assist IPC-498 Enabling PGM Router Assist with a Virtual Host Interface IPC-499 Enabling PGM Router Assist with a Physical Interface IPC-499 Monitoring and Maintaining PGM Host and Router Assist IPC-499 Monitoring and Maintaining PGM H
Contents Integrated UDLR Tunnel, IGMP UDLR, and IGMP Proxy Example Using IP Multicast Tools IPC-521 Multicast Routing Monitor Overview Benefits IPC-521 Restrictions IPC-522 IPC-521 MRM Configuration Task List IPC-522 Configuring a Test Sender and Test Receiver Monitoring Multiple Groups IPC-523 Configuring a Manager IPC-524 Conducting an MRM Test IPC-524 Monitoring IP Multicast Routing MRM Configuration Example IPC-522 IPC-525 Monitoring and Maintaining MRM IPC-525 IPC-526 Configuring Router-Port
Contents Monitoring and Maintaining DVMRP IPC-545 DVMRP Configuration Examples IPC-545 DVMRP Interoperability Example IPC-545 DVMRP Tunnel Example IPC-545 INDEX Cisco IOS IP Configuration Guide xxviii
About Cisco IOS Software Documentation This chapter discusses the objectives, audience, organization, and conventions of Cisco IOS software documentation. It also provides sources for obtaining documentation from Cisco Systems. Documentation Objectives Cisco IOS software documentation describes the tasks and commands necessary to configure and maintain Cisco networking devices.
About Cisco IOS Software Documentation Documentation Organization Figure 1 shows the Cisco IOS software documentation modules. Note Figure 1 The abbreviations (for example, FC and FR) next to the book icons are page designators, which are defined in a key in the index of each document to help you with navigation. The bullets under each module list the major technology areas discussed in the corresponding books.
About Cisco IOS Software Documentation Documentation Organization Cisco IOS Dial Technologies Configuration Guide TC BC Cisco IOS Terminal Services Configuration Guide Cisco IOS Bridging and IBM Networking Configuration Guide B2R B1R DR Cisco IOS Dial Technologies Command Reference TR Module DC/DR: • Preparing for Dial Access • Modem and Dial Shelf Configuration and Management • ISDN Configuration • Signalling Configuration • Dial-on-Demand Routing Configuration • Dial-Backup Configuration • Dial
About Cisco IOS Software Documentation Documentation Organization Master Indexes Two master indexes provide indexing information for the Cisco IOS software documentation set: an index for the configuration guides and an index for the command references. Individual books also contain a book-specific index. The master indexes provide a quick way for you to find a command when you know the command name but not which module contains the command.
About Cisco IOS Software Documentation New and Changed Information New and Changed Information The following is new or changed information since the last release of the Cisco IOS IP and IP routing publications: • The title of the Cisco IOS IP and IP Routing Configuration Guide has been changed to Cisco IOS IP Configuration Guide.
About Cisco IOS Software Documentation Document Conventions Command syntax descriptions use the following conventions: Convention Description boldface Boldface text indicates commands and keywords that you enter literally as shown. italics Italic text indicates arguments for which you supply values. [x] Square brackets enclose an optional element (keyword or argument). | A vertical line indicates a choice within an optional or required set of keywords or arguments.
About Cisco IOS Software Documentation Obtaining Documentation Obtaining Documentation The following sections provide sources for obtaining documentation from Cisco Systems. World Wide Web The most current Cisco documentation is available on the World Wide Web at the following website: http://www.cisco.com Translated documentation is available at the following website: http://www.cisco.com/public/countries_languages.
About Cisco IOS Software Documentation Obtaining Technical Assistance To submit your comments by mail, use the response card behind the front cover of your document, or write to the following address: Cisco Systems, Inc. Document Resource Connection 170 West Tasman Drive San Jose, CA 95134-9883 We appreciate your comments. Obtaining Technical Assistance Cisco provides Cisco.com as a starting point for all technical assistance.
About Cisco IOS Software Documentation Obtaining Technical Assistance P3 and P4 level problems are defined as follows: • P3—Your network performance is degraded. Network functionality is noticeably impaired, but most business operations continue. • P4—You need information or assistance on Cisco product capabilities, product installation, or basic product configuration. In each of the above cases, use the Cisco TAC website to quickly find answers to your questions. To register for Cisco.
About Cisco IOS Software Documentation Obtaining Technical Assistance Cisco IOS IP Configuration Guide xxxviii
Using Cisco IOS Software This chapter provides helpful tips for understanding and configuring Cisco IOS software using the command-line interface (CLI).
Using Cisco IOS Software Getting Help Table 1 describes how to access and exit various common command modes of the Cisco IOS software. It also shows examples of the prompts displayed for each mode. Table 1 Accessing and Exiting Command Modes Command Mode Access Method Prompt Exit Method User EXEC Log in. Router> Use the logout command. Privileged EXEC From user EXEC mode, use the enable EXEC command. Router# To return to user EXEC mode, use the disable command.
Using Cisco IOS Software Getting Help Example: How to Find Command Options This section provides an example of how to display syntax for a command. The syntax can consist of optional or required keywords and arguments. To display keywords and arguments for a command, enter a question mark (?) at the configuration prompt or after entering part of a command followed by a space. The Cisco IOS software displays a list and brief description of available keywords and arguments.
Using Cisco IOS Software Getting Help Table 2 How to Find Command Options (continued) Command Comment Router(config-if)# ? Interface configuration commands: . . .
Using Cisco IOS Software Using the no and default Forms of Commands Table 2 How to Find Command Options (continued) Command Comment Router(config-if)# ip address ? A.B.C.D IP address negotiated IP Address negotiated over PPP Router(config-if)# ip address Enter the command that you want to configure for the interface. This example uses the ip address command. Enter ? to display what you must enter next on the command line. In this example, you must enter an IP address or the negotiated keyword.
Using Cisco IOS Software Saving Configuration Changes have variables set to certain default values. In these cases, the default form of the command enables the command and sets the variables to their default values. The Cisco IOS software command reference publications describe the effect of the default form of a command if the command functions differently than the no form.
Using Cisco IOS Software Identifying Supported Platforms Identifying Supported Platforms Cisco IOS software is packaged in feature sets consisting of software images that support specific platforms. The feature sets available for a specific platform depend on which Cisco IOS software images are included in a release.
Using Cisco IOS Software Identifying Supported Platforms Cisco IOS IP Configuration Guide xlvi
IP Overview The Internet Protocol (IP) is a packet-based protocol used to exchange data over computer networks. IP handles addressing, fragmentation, reassembly, and protocol demultiplexing. It is the foundation on which all other IP protocols (collectively referred to as the IP Protocol suite) are built. A network-layer protocol, IP contains addressing and control information that allows data packets to be routed. The Transmission Control Protocol (TCP) is built upon the IP layer.
IP Overview IP Routing Protocols Server load balancing allows a network administrator to define a virtual server to represent a group of real servers. For more information on this feature, see the “Configuring Server Load Balancing” chapter. Mobile IP, which allows users to roam and maintain connectivity beyond their home subnet while consistently maintaining their IP address, is described in the “Configuring Mobile IP” chapter.
IP Overview IP Routing Protocols Note Many routing protocol specifications refer to routers as gateways, so the word gateway often appears as part of routing protocol names. However, a router usually is defined as a Layer 3 internetworking device, whereas a protocol translation gateway usually is defined as a Layer 7 internetworking device.
IP Overview IP Multicast For example, RIP uses a hop-count metric and IGRP uses a five-element vector of metric information. If routing information is being exchanged between different networks that use different routing protocols, you can use many configuration options to filter the exchange of routing information. The Cisco IOS software can handle simultaneous operation of up to 30 dynamic IP routing processes.
IP Addressing and Services
Configuring IP Addressing This chapter describes how to configure IP addressing. For a complete description of the IP addressing commands in this chapter, refer to the “IP Addressing Commands” chapter of the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring IP Addressing Assigning IP Addresses to Network Interfaces Table 3 Reserved and Available IP Addresses Class Address or Range Status A 0.0.0.0 1.0.0.0 to 126.0.0.0 127.0.0.0 Reserved Available Reserved B 128.0.0.0 to 191.254.0.0 191.255.0.0 Available Reserved C 192.0.0.0 192.0.1.0 to 223.255.254 223.255.255.0 Reserved Available Reserved D 224.0.0.0 to 239.255.255.255 Multicast group addresses E 240.0.0.0 to 255.255.255.254 255.255.255.
Configuring IP Addressing Assigning IP Addresses to Network Interfaces Assigning Multiple IP Addresses to Network Interfaces Cisco IOS software supports multiple IP addresses per interface. You can specify an unlimited number of secondary addresses. Secondary IP addresses can be used in a variety of situations. The following are the most common applications: Note • There might not be enough host addresses for a particular network segment.
Configuring IP Addressing Assigning IP Addresses to Network Interfaces You can use the all 0s and all 1s subnet (131.108.255.0), even though it is discouraged. Configuring interfaces for the all 1s subnet is explicitly allowed. However, if you need the entire subnet space for your IP address, use the following command in global configuration mode to enable subnet 0: Command Purpose Router(config)# ip subnet-zero Enables the use of subnet zero for interface addresses and routing updates.
Configuring IP Addressing Assigning IP Addresses to Network Interfaces Figure 2 No IP Classless Routing 128.0.0.0/8 128.20.4.1 128.20.0.0 Bit bucket 128.20.1.0 128.20.3.0 128.20.4.1 S3285 128.20.2.0 Host To prevent the Cisco IOS software from forwarding packets destined for unrecognized subnets to the best supernet route possible, use the following command in global configuration mode: Command Purpose Router(config)# no ip classless Disables classless routing behavior.
Configuring IP Addressing Configuring Address Resolution Methods Note Using an unnumbered serial line between different major networks requires special care. If, at each end of the link, different major networks are assigned to the interfaces you specified as unnumbered, any routing protocols running across the serial line should be configured to not advertise subnet information.
Configuring IP Addressing Configuring Address Resolution Methods The software uses three forms of address resolution: Address Resolution Protocol (ARP), proxy ARP, and Probe (similar to ARP). The software also uses the Reverse Address Resolution Protocol (RARP). ARP, proxy ARP, and RARP are defined in RFCs 826, 1027, and 903, respectively. Probe is a protocol developed by the Hewlett-Packard Company (HP) for use on IEEE-802.3 networks. ARP is used to associate IP addresses with media or MAC addresses.
Configuring IP Addressing Configuring Address Resolution Methods Use the following command in interface configuration mode to set the length of time an ARP cache entry will stay in the cache: Command Purpose Router(config-if)# arp timeout seconds Sets the length of time an ARP cache entry will stay in the cache. To display the type of ARP being used on a particular interface and also display the ARP timeout value, use the show interfaces EXEC command.
Configuring IP Addressing Configuring Address Resolution Methods Configuring Local-Area Mobility Local-area mobility provides the ability to relocate IP hosts within a limited area without reassigning host IP addresses and without changes to the host software. Local-area mobility is supported on Ethernet, Token Ring, and FDDI interfaces only.
Configuring IP Addressing Configuring Address Resolution Methods To keep track of domain names, IP has defined the concept of a name server, whose job is to hold a cache (or database) of names mapped to IP addresses. To map domain names to IP addresses, you must first identify the host names, then specify a name server, and enable the Domain Naming System (DNS), the global naming scheme of the Internet that uniquely identifies network devices.
Configuring IP Addressing Configuring Address Resolution Methods Specifying a Name Server To specify one or more hosts (up to six) that can function as a name server to supply name information for the DNS, use the following command in global configuration mode: Command Purpose Router(config)# ip name-server server-address1 [server-address2...server-address6] Specifies one or more hosts that supply name information.
Configuring IP Addressing Configuring Address Resolution Methods Configuring HP Probe Proxy Name Requests HP Probe Proxy support allows the Cisco IOS software to respond to HP Probe Proxy name requests. These requests are typically used at sites that have HP equipment and are already using HP Probe Proxy. Tasks associated with HP Probe Proxy are shown in the following two tables.
Configuring IP Addressing Configuring Address Resolution Methods Figure 3 illustrates four routers connected to an NBMA network. Within the network are ATM or SMDS switches necessary for the routers to communicate with each other. Assume that the switches have virtual circuit (VC) connections represented by hops 1, 2, and 3 of the figure. When Router A attempts to forward an IP packet from the source host to the destination host, NHRP is triggered.
Configuring IP Addressing Configuring Address Resolution Methods Each Next Hop Server serves a set of destination hosts, which might be directly connected to the NBMA network. Next Hop Servers cooperatively resolve the NBMA next hop addresses within their NBMA network. Next Hop Servers typically also participate in protocols used to disseminate routing information across (and beyond the boundaries of) the NBMA network, and might support ARP service.
Configuring IP Addressing Configuring Address Resolution Methods Enabling NHRP on an Interface To enable NHRP for an interface on a router, use the following command in interface configuration mode. In general, all NHRP stations within a logical NBMA network must be configured with the same network identifier. Command Purpose Router(config-if)# ip nhrp network-id number Enables NHRP on an interface.
Configuring IP Addressing Configuring Address Resolution Methods Configuring NHRP Authentication Configuring an authentication string ensures that only routers configured with the same string can communicate using NHRP. Therefore, if the authentication scheme is to be used, the same string must be configured in all devices configured for NHRP on a fabric.
Configuring IP Addressing Configuring Address Resolution Methods Triggering NHRP on a per-Destination Basis By default, when the software attempts to send a data packet to a destination for which it has determined that NHRP can be used, it sends an NHRP request for that destination.
Configuring IP Addressing Configuring Address Resolution Methods NHRP Configuration Task List To configure the NHRP triggering and teardown of SVCs based on traffic rate, perform the tasks described in the following sections. The tasks in the first section are required, the tasks in the remaining section are optional.
Configuring IP Addressing Configuring Address Resolution Methods If your Cisco hardware has a Virtual Interface Processor, version 2 adapter, you must perform the following task to change the sampling time. By default, the port adapter sends the traffic statistics to the Route Processor every 10 seconds. If you are using NHRP in dCEF switching mode, you must change this update rate to 5 seconds.
Configuring IP Addressing Configuring Address Resolution Methods Suppressing Forward and Reverse Record Options To dynamically detect link layer filtering in NBMA networks (for example, SMDS address screens), and to provide loop detection and diagnostic capabilities, NHRP incorporates a Route Record in request and reply packets.
Configuring IP Addressing Enabling IP Routing Configuring a GRE Tunnel for Multipoint Operation You can enable a generic routing encapsulation (GRE) tunnel to operate in multipoint fashion. A tunnel network of multipoint tunnel interfaces can be thought of as an NBMA network. To configure the tunnel, use the following commands in interface configuration mode: Command Purpose Step 1 Router(config-if)# tunnel mode gre ip multipoint Enables a GRE tunnel to be used in multipoint fashion.
Configuring IP Addressing Enabling IP Routing Routing Assistance When IP Routing Is Disabled The Cisco IOS software provides three methods by which the router can learn about routes to other networks when IP routing is disabled and the device is acting as an IP host.
Configuring IP Addressing Enabling IP Routing ICMP Router Discovery Protocol The Cisco IOS software provides a third method, called router discovery, by which the router dynamically learns about routes to other networks using the ICMP Router Discovery Protocol IRDP). IRDP allows hosts to locate routers. When the device operates as a client, router discovery packets are generated. When the device operates as a host, router discovery packets are received.
Configuring IP Addressing Enabling IP Bridging Command Purpose Router(config-if)# ip irdp preference number Sets the IRDP preference level of the device. Router(config-if)# ip irdp address address [number] Specifies an IRDP address and preference to proxy-advertise. The Cisco IOS software can proxy-advertise other machines that use IRDP; however, this practice is not recommended because it is possible to advertise nonexistent machines or machines that are down.
Configuring IP Addressing Configuring Broadcast Packet Handling Configuring Broadcast Packet Handling A broadcast is a data packet destined for all hosts on a particular physical network. Network hosts recognize broadcasts by special addresses. Broadcasts are heavily used by some protocols, including several important Internet protocols. Control of broadcast messages is an essential responsibility of the IP network administrator.
Configuring IP Addressing Configuring Broadcast Packet Handling To enable forwarding of IP directed broadcasts, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip directed-broadcast [access-list-number] Enables directed broadcast-to-physical broadcast translation on an interface. Forwarding UDP Broadcast Packets and Protocols Network hosts occasionally use User Datagram Protocol (UDP) broadcasts to determine address, configuration, and name information.
Configuring IP Addressing Configuring Broadcast Packet Handling Establishing an IP Broadcast Address The Cisco IOS software supports IP broadcasts on both LANs and WANs. There are several ways to indicate an IP broadcast address. Currently, the most popular way, and the default, is an address consisting of all 1s (255.255.255.255), although the software can be configured to generate any form of IP broadcast address. Cisco software can receive and understand any form of IP broadcast.
Configuring IP Addressing Configuring Broadcast Packet Handling In order to be considered for flooding, packets must meet the following criteria. (Note that these are the same conditions used to consider packet forwarding using IP helper addresses.) • The packet must be a MAC-level broadcast. • The packet must be an IP-level broadcast.
Configuring IP Addressing Configuring Network Address Translation Configuring Network Address Translation Two key problems facing the Internet are depletion of IP address space and scaling in routing. Network Address Translation (NAT) is a feature that allows the IP network of an organization to appear from the outside to use different IP address space than what it is actually using.
Configuring IP Addressing Configuring Network Address Translation A router configured with NAT must not advertise the local networks to the outside. However, routing information that NAT receives from the outside can be advertised in the stub domain as usual. NAT Terminology As mentioned previously, the term inside refers to those networks that are owned by an organization and that must be translated.
Configuring IP Addressing Configuring Network Address Translation Translating Inside Source Addresses You can translate your own IP addresses into globally unique IP addresses when communicating outside of your network. You can configure static or dynamic inside source translation as follows: • Static translation establishes a one-to-one mapping between your inside local address and an inside global address.
Configuring IP Addressing Configuring Network Address Translation Host 1.1.1.1 receives the packet and continues the conversation. The router performs Steps 2 through 5 for each packet.
Configuring IP Addressing Configuring Network Address Translation Packets that enter the router through the inside interface and packets sourced from the router are checked against the access list for possible NAT candidates. The access list is used to specify which traffic is to be translated.
Configuring IP Addressing Configuring Network Address Translation Figure 5 NAT Overloading Inside Global Addresses Inside 5 DA 1.1.1.1 3 SA 2.2.2.2 Internet SA 1.1.1.1 1 Host B 9.6.7.3 4 S4791 1.1.1.2 4 DA 2.2.2.2 DA 2.2.2.2 1.1.1.1 2 Host C 6.5.4.7 NAT table Protocol Inside Local IP address:port TCP TCP 1.1.1.2:1723 1.1.1.1:1024 Inside Global IP Outside Global address:port IP address:port 2.2.2.2:1723 2.2.2.2:1024 6.5.4.7:23 9.6.7.
Configuring IP Addressing Configuring Network Address Translation Command Purpose Step 3 Router(config)# ip nat inside source list access-list-number pool name overload Establishes dynamic source translation, specifying the access list defined in the prior step. Step 4 Router(config)# interface type number Specifies the inside interface. Step 5 Router(config-if)# ip nat inside Marks the interface as connected to the inside.
Configuring IP Addressing Configuring Network Address Translation Figure 6 NAT Translating Overlapping Addresses DNS request for host C address SA=2.2.2.2 DA=x.x.x.x DNS server x.x.x.x 1.1.1.1 Internet DNS request for host C address Host C 1.1.1.3 SA=1.1.1.1 DA=x.x.x.x DNS response from x.x.x.x DNS response from x.x.x.x SA=x.x.x.x DA=1.1.1.1 C=3.3.3.3 SA=x.x.x.x DA=2.2.2.2 C=1.1.1.3 1.1.1.1 message to host C 1.1.1.1 message to host C SA=1.1.1.1 DA=3.3.3.3 SA=2.2.2.2 DA=1.1.1.
Configuring IP Addressing Configuring Network Address Translation Configuring Static Translation To configure static SA address translation, use the following commands in global configuration mode: Command Purpose Step 1 Router(config)# ip nat outside source static global-ip local-ip Establishes static translation between an outside local address and an outside global address. Step 2 Router(config)# interface type number Specifies the inside interface.
Configuring IP Addressing Configuring Network Address Translation addresses from a rotary pool. Allocation is done on a round-robin basis, and only when a new connection is opened from the outside to the inside. Non-TCP traffic is passed untranslated (unless other translations are in effect). Figure 7 illustrates this feature. Figure 7 NAT TCP Load Distribution Inside B 1 DA 1.1.1.127 1.1.1.1 DA 1.1.1.1 3 Real hosts 1.1.1.2 9.6.7.3 Intranet 5 SA 1.1.1.127 C 4 SA 1.1.1.1 1.1.1.3 6.5.4.
Configuring IP Addressing Configuring Network Address Translation Command Purpose Step 1 Router(config)# ip nat pool name start-ip end-ip {netmask netmask | prefix-length prefix-length} type rotary Defines a pool of addresses containing the addresses of the real hosts. Step 2 Router(config)# access-list access-list-number permit source [source-wildcard] Defines an access list permitting the address of the virtual host.
Configuring IP Addressing Configuring Network Address Translation Command Purpose Router(config)# ip nat translation icmp-timeout seconds Changes the ICMP timeout value from 1 minute. Router(config)# ip nat translation syn-timeout seconds Changes the Synchronous (SYN) timeout value from 1 minute. Monitoring and Maintaining NAT By default, dynamic address translations will time out from the NAT translation table at some point.
Configuring IP Addressing Monitoring and Maintaining IP Addressing To specify a port other than the default port, use the following command in global configuration mode: Command Purpose Router(config)# ip nat service skinny tcp port number Displays port number on which the CCM is listening for skinny messages. Monitoring and Maintaining IP Addressing To monitor and maintain your network, perform the tasks described in the following sections.
Configuring IP Addressing Monitoring and Maintaining IP Addressing To specify the format in which netmasks appear for the current session, use the following command in EXEC mode: Command Purpose Router# term ip netmask-format {bitcount | decimal | hexadecimal} Specifies the format of network masks for the current session.
Configuring IP Addressing IP Addressing Examples Command Purpose Router# trace [destination] Traces packet routes through the network (privileged mode). Router# trace ip destination Traces packet routes through the network (user mode). See the “ping Command Example” section at the end of this chapter for an example of pinging.
Configuring IP Addressing IP Addressing Examples • Changing the Rate for Triggering SVCs Example • Applying NHRP Rates to Specific Destinations Example • NHRP on a Multipoint Tunnel Example • Broadcasting Examples • NAT Configuration Examples • ping Command Example Creating a Network from Separated Subnets Example In the following example, subnets 1 and 2 of network 131.108.0.0 are separated by a backbone, as shown in Figure 8.
Configuring IP Addressing IP Addressing Examples ip address 145.22.4.67 255.255.255.0 interface serial 1 ip unnumbered ethernet 0 IP Domains Example The following example establishes a domain list with several alternate domain names: ip domain list csi.com ip domain list telecomprog.edu ip domain-list merit.
Configuring IP Addressing IP Addressing Examples Figure 9 Two Logical NBMA Networks over One Physical NBMA Network Destination host ip nhrp network-id 7 Router E ip nhrp network-id 7 ip nhrp network-id 2 Router D ip nhrp network-id 7 Router C Router B ip nhrp network-id 2 ip nhrp network-id 2 Router A = Statically configured tunnel endpoints or permanent virtual circuits = Dynamically created virtual circuits S3230 Source host The physical configuration of the five routers in Figure 9 might act
Configuring IP Addressing IP Addressing Examples Figure 10 Physical Configuration of a Sample NBMA Network Source host Router A Router B Router C Router E S3231 Destination host Router D Refer again to Figure 9. Initially, before NHRP has resolved any NBMA addresses, IP packets from the source host to the destination host travel through all five routers connected to the switch before reaching the destination.
Configuring IP Addressing IP Addressing Examples The significant portions of the configurations for routers A, B, and C follow: Router A Configuration interface ATM0/0 ip address 10.1.0.1 255.255.0.0 ip nhrp network-id 1 map-group a atm nsap-address 11.1111.11.111111.1111.1111.1111.1111.1111.1111.11 atm rate-queue 1 10 atm pvc 1 0 5 qsaal router ospf 1 network 10.0.0.0 0.255.255.255 area 0 map-list a ip 10.1.0.3 atm-nsap 33.3333.33.333333.3333.3333.3333.3333.3333.3333.
Configuring IP Addressing IP Addressing Examples map-list a ip 10.1.0.1 atm-nsap 11.1111.11.111111.1111.1111.1111.1111.1111.1111.11 map-list b ip 10.2.0.2 atm-nsap 22.2222.22.222222.2222.2222.2222.2222.2222.2222.22 Changing the Rate for Triggering SVCs Example Figure 11 and the example configuration following it show how to configure a threshold of 100 kbps for triggering SVCs and 50 kbps for tearing down SVCs. Figure 11 Using NHRP and Triggering SVCs Router B Loopback address 140.206.59.
Configuring IP Addressing IP Addressing Examples interface Fddi1/0/0 ip address 10.2.1.55 255.255.255.0 no ip directed-broadcast no ip mroute-cache no keepalive ! router ospf 1 passive-interface Fddi1/0/0 network 10.2.1.0 0.0.0.255 area 1 network 140.206.58.0 0.0.0.255 area 1 ! router bgp 7170 no synchronization network 140.206.0.0 neighbor 10.2.1.36 remote-as 102 neighbor 140.206.59.130 remote-as 7170 neighbor 140.206.59.130 update-source Loopback0 neighbor 140.206.59.
Configuring IP Addressing IP Addressing Examples Router C Configuration ip cef ip cef accounting non-recursive ! interface Loopback0 ip address 140.206.58.131 255.255.255.255 no ip directed-broadcast no ip mroute-cache ! interface ATM0/0 no ip address no ip directed-broadcast no ip mroute-cache atm pvc 5 0 5 qsaal atm pvc 16 0 16 ilmi ! interface ATM0/0.1 multipoint ip address 140.206.58.56 255.255.255.
Configuring IP Addressing IP Addressing Examples NHRP on a Multipoint Tunnel Example With multipoint tunnels, a single tunnel interface may be connected to multiple neighboring routers. Unlike point-to-point tunnels, a tunnel destination need not be configured. In fact, if configured, the tunnel destination must correspond to an IP multicast address.
Configuring IP Addressing IP Addressing Examples ip nhrp network-id 1 ip nhrp nhs 11.0.0.4 tunnel source ethernet 0 tunnel mode gre multipoint tunnel key 1 interface ethernet 0 ip address 10.0.0.3 255.0.0.0 Router D Configuration interface tunnel 0 no ip redirects ip address 11.0.0.4 255.0.0.0 ip nhrp map 11.0.0.1 10.0.0.1 ip nhrp network-id 1 ip nhrp nhs 11.0.0.1 tunnel source ethernet 0 tunnel mode gre multipoint tunnel key 1 interface ethernet 0 ip address 10.0.0.4 255.0.0.
Configuring IP Addressing IP Addressing Examples A directed broadcast address includes the network or subnet fields. For example, if the network address is 128.1.0.0, the address 128.1.255.255 indicates all hosts on network 128.1.0.0, which would be a directed broadcast. If network 128.1.0.0 has a subnet mask of 255.255.255.0 (the third octet is the subnet field), the address 128.1.5.255 specifies all hosts on subnet 5 of network 128.1.0.0—another directed broadcast.
Configuring IP Addressing IP Addressing Examples Figure 13 IP Helper Addresses Network 192.168.1.0 E1 E2 Server 192.168.1.19 Server 10.44.23.7 S1017a Network 10.44.0.0 The following example shows the configuration: ip forward-protocol udp ! interface ethernet 1 ip helper-address 10.44.23.7 interface ethernet 2 ip helper-address 192.168.1.19 NAT Configuration Examples The following sections show NAT configuration examples.
Configuring IP Addressing IP Addressing Examples ip nat inside source route-map ip nat inside source route-map ! interface Serial0/0 ip nat outside ! interface Serial0/1 ip nat outside ! route-map provider1-map permit match ip address 1 match interface Serial0/0 ! route-map provider2-map permit match ip address 1 match interface Serial0/1 provider1-map pool provider1-space provider2-map pool providere2-space 10 10 Overloading Inside Global Addresses Example The following example creates a pool of addre
Configuring IP Addressing IP Addressing Examples TCP Load Distribution Example In the following example, the goal is to define a virtual address, connections to which are distributed among a set of real hosts. The pool defines the addresses of the real hosts. The access list defines the virtual address. If a translation does not already exist, TCP packets from serial interface 0 (the outside interface) whose destination matches the access list are translated to an address from the pool.
Configuring IP Addressing IP Addressing Examples Cisco IOS IP Configuration Guide IPC-64
Configuring DHCP This chapter describes how to configure Dynamic Host Configuration Protocol (DHCP). For a complete description of the DHCP commands listed in this chapter, refer to the “DHCP Commands” chapter of the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring DHCP DHCP Server Overview Figure 14 shows the basic steps that occur when a DHCP client requests an IP address from a DHCP Server. The client, Host A, sends a DHCPDISCOVER broadcast message to locate a Cisco IOS DHCP Server. A DHCP Server offers configuration parameters (such as an IP address, a MAC address, a domain name, and a lease for the IP address) to the client in a DHCPOFFER unicast message.
Configuring DHCP DHCP Client Overview Using automatic IP address assignment at each remote site substantially reduces Internet access costs. Static IP addresses are considerably more expensive to purchase than are automatically allocated IP addresses. • Reduced client configuration tasks and costs Because DHCP is easy to configure, it minimizes operational overhead and costs associated with device configuration tasks and eases deployment by nontechnical users.
Configuring DHCP DHCP Configuration Task List DHCP Configuration Task List The DHCP Server database is organized as a tree. The root of the tree is the address pool for natural networks, branches are subnetwork address pools, and leaves are manual bindings to clients. Subnetworks inherit network parameters and clients inherit subnetwork parameters. Therefore, common parameters, for example the domain name, should be configured at the highest (network or subnetwork) level of the tree.
Configuring DHCP DHCP Configuration Task List Configuring a DHCP Database Agent or Disabling DHCP Conflict Logging A DHCP database agent is any host—for example, an FTP, TFTP, or rcp server—that stores the DHCP bindings database. You can configure multiple DHCP database agents and you can configure the interval between database updates and transfers for each agent.
Configuring DHCP DHCP Configuration Task List Configuring the DHCP Address Pool Subnet and Mask To configure a subnet and mask for the newly created DHCP address pool, which contains the range of available IP addresses that the DHCP Server may assign to clients, use the following command in DHCP pool configuration mode: Command Purpose Router(dhcp-config)# network network-number [mask | /prefix-length] Specifies the subnet network number and mask of the DHCP address pool.
Configuring DHCP DHCP Configuration Task List Command Purpose Router(dhcp-config)# netbios-name-server address [address2 ... address8] Specifies the NetBIOS WINS server that is available to a Microsoft DHCP client. One address is required; however, you can specify up to eight addresses in one command line. Configuring the NetBIOS Node Type for the Client The NetBIOS node type for Microsoft DHCP clients can be one of four settings: broadcast, peer-to-peer, mixed, or hybrid.
Configuring DHCP DHCP Configuration Task List Manual bindings are IP addresses that have been manually mapped to the MAC addresses of hosts that are found in the DHCP database. Manual bindings are stored in NVRAM on the DHCP Server. Manual bindings are just special address pools. There is no limit on the number of manual bindings but you can only configure one manual binding per host pool.
Configuring DHCP DHCP Configuration Task List Configuring a DHCP Server Boot File The boot file is used to store the boot image for the client. The boot image is generally the operating system the client uses to load. To specify a boot file for the DHCP client, use the following command in DHCP pool configuration mode: Command Purpose Router(dhcp-config)# bootfile filename Specifies the name of the file that is used as a boot image.
Configuring DHCP DHCP Configuration Task List Configuring DHCP Server Options Import and Autoconfiguration The Cisco IOS DHCP server can dynamically configure options such as the DNS and WINS addresses to respond to DHCP requests from local clients behind the customer premises equipment (CPE). Previously, network administrators needed to manually configure the Cisco IOS DHCP server on each device enabled with this feature.
Configuring DHCP Monitoring and Maintaining the DHCP Server Configuring the Relay Agent Information Option in BOOTREPLY Messages To configure the DHCP Server to validate the relay agent information option in forwarded BOOTREPLY messages, use the following command in global configuration mode: Command Purpose Router(config)# ip dhcp relay information check Configures the DHCP Server to check that the relay agent information option in forwarded BOOTREPLY messages is valid.
Configuring DHCP Configuration Examples Command Purpose Router# clear ip dhcp server statistics Resets all DHCP Server counters to 0. Router# clear ip route [vrf vrf-name] dhcp [ip-address] Removes routes from the routing table added by the Cisco IOS DHCP Server and Relay Agent for the DHCP clients on unnumbered interfaces.
Configuring DHCP Configuration Examples DHCP Database Agent Configuration Example The following example stores bindings on host 172.16.4.253. The file transfer protocol is FTP. The server should wait 2 minutes (120 seconds) before writing database changes. ip dhcp database ftp://user:password@172.16.4.253/router-dhcp write-delay 120 DHCP Address Pool Configuration Example In the following example, three DHCP address pools are created: one in network 172.16.0.0, one in subnetwork 172.16.1.
Configuring DHCP Configuration Examples Manual Bindings Configuration Example The following example creates a manual binding for a client named Mars.cisco.com. The MAC address of the client is 02c7.f800.0422 and the IP address of the client is 172.16.2.254. ip dhcp pool Mars host 172.16.2.254 hardware-address 02c7.f800.0422 ieee802 client-name Mars Because attributes are inherited, the previous configuration is equivalent to the following: ip dhcp pool Mars host 172.16.2.254 mask 255.255.255.
Configuring DHCP Configuration Examples DHCP Server Options Import and Autoconfiguration Example The following example shows a remote and central server configured to support DHCP options import and autoconfiguration. The central server is configured to automatically update DHCP options, such as DNS and WINs addresses, within the DHCP pools. In response to a DHCP request from a local client behind CPE equipment, the remote server can request or “import” these option parameters from the centralized server.
Configuring DHCP Configuration Examples speed auto Cisco IOS IP Configuration Guide IPC-80
Configuring IP Services This chapter describes how to configure optional IP services. For a complete description of the IP services commands in this chapter, refer to the “IP Services Commands” chapter of the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring IP Services Managing IP Connections To manage various aspects of IP connections, perform the optional tasks described in the following sections: • Enabling ICMP Protocol Unreachable Messages (Optional) • Enabling ICMP Redirect Messages (Optional) • Enabling ICMP Mask Reply Messages (Optional) • Understanding Path MTU Discovery (Optional) • Setting the MTU Packet Size (Optional) • Enabling IP Source Routing (Optional) • Configuring Simplex Ethernet Interfaces (Optional) • Configur
Configuring IP Services Managing IP Connections To enable the sending of ICMP redirect messages if this feature was disabled, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip redirects Enables the sending of ICMP redirect messages to learn routes. Enabling ICMP Mask Reply Messages Occasionally, network devices must know the subnet mask for a particular subnetwork in the internetwork.
Configuring IP Services Managing IP Connections because the 512-byte router is unable to forward it. All packets larger than 512 bytes are dropped in this case. The second router returns an ICMP destination unreachable message to the source of the datagram with its Code field indicating, “Fragmentation needed and DF set.” To support IP Path MTU Discovery, it would also include the MTU of the next hop network link in the low-order bits of an unused header field.
Configuring IP Services Managing IP Connections IP provides a provision known as source routing that allows the source IP host to specify a route through the IP network. Source routing is specified as an option in the IP header. If source routing is specified, the software forwards the packet according to the specified source route. This feature is employed when you want to force a packet to take a certain route through the network. The default is to perform source routing.
Configuring IP Services Managing IP Connections To configure and maintain the DRP Server Agent, perform the tasks described in the following sections. The task in the first section is required; the tasks in the remaining sections are optional.
Configuring IP Services Filtering IP Packets Using Access Lists Command Purpose Step 4 Router(config-keychain-key)# key-string text In key-chain key configuration mode, identifies the key string. Step 5 Router(config-keychain-key)# accept-lifetime start-time {infinite | end-time | duration seconds} (Optional) Specifies the time period during which the key can be received.
Configuring IP Services Filtering IP Packets Using Access Lists 2. Apply the access list to interfaces or terminal lines. These and other tasks are described in this section and are labeled as required or optional. Either the first or second task is required, depending on whether you identify your access list with a number or a name.
Configuring IP Services Filtering IP Packets Using Access Lists To create a standard access list, use the following commands in global configuration mode: Command Purpose Step 1 Router(config)# access-list access-list-number remark remark Indicates the purpose of the deny or permit statement.1 Step 2 Router(config)# access-list access-list-number {deny | permit} source [source-wildcard] [log] Defines a standard IP access list using a source address and wildcard.
Configuring IP Services Filtering IP Packets Using Access Lists To create an extended access list, use the following commands in global configuration mode: Command Purpose Step 1 Router(config)# access-list access-list-number remark remark Indicates the purpose of the deny or permit statement.
Configuring IP Services Filtering IP Packets Using Access Lists Note In a standard access list, if you omit the mask from an associated IP host address access list specification, 0.0.0.0 is assumed to be the mask. Note Autonomous switching is not used when you have extended access lists. After creating an access list, you must apply it to a line or interface, as shown in the section “Applying Access Lists” later in this chapter.
Configuring IP Services Filtering IP Packets Using Access Lists To create an extended access list, use the following commands beginning in global configuration mode: Step 1 Router(config)# ip access-list extended name Defines an extended IP access list using a name and enters extended named access list configuration mode. Step 2 Router(config-ext-nacl)# remark remark Allows you to comment about the following deny or permit statement in a named access list.
Configuring IP Services Filtering IP Packets Using Access Lists Note When making the standard and extended access list, remember that, by default, the end of the access list contains an implicit deny statement for everything if it did not find a match before reaching the end. Further, with standard access lists, if you omit the mask from an associated IP host address access list specification, 0.0.0.0 is assumed to be the mask.
Configuring IP Services Filtering IP Packets Using Access Lists The behavior of access-list entries regarding the presence or absence of the fragments keyword can be summarized as follows: If the Access-List Entry has... Then.. ...no fragments keyword, and assuming all of the access-list entry information matches, For an access-list entry containing only Layer 3 information: • The entry is applied to nonfragmented packets, initial fragments and noninitial fragments.
Configuring IP Services Filtering IP Packets Using Access Lists The fragments keyword can be applied to dynamic access lists also. Packet fragments of IP datagrams are considered individual packets and each counts individually as a packet in access list accounting and access list violation counts. Note The fragments keyword cannot solve all cases involving access lists and IP fragments.
Configuring IP Services Filtering IP Packets Using Access Lists Enabling Turbo Access Control Lists The Turbo Access Control Lists (Turbo ACL) feature processes access lists more expediently than conventional access lists. This feature enables Cisco 7200 and 7500 series routers, and Cisco 12000 series Gigabit Switch Routers, to evaluate ACLs for more expedient packet classification and access checks.
Configuring IP Services Filtering IP Packets Using Access Lists Verifying Turbo ACLs Use the show access-list compiled EXEC command to verify that the Turbo ACL feature has been successfully configured on your router. This command also displays the memory overhead of the Turbo ACL tables for each access list.
Configuring IP Services Filtering IP Packets Using Access Lists time-range command is described in the “Performing Basic System Management” chapter of the Cisco IOS Configuration Fundamentals Configuration Guide. See the “Time Range Applied to an IP Access List Example” section at the end of this chapter for a configuration example of IP time ranges.
Configuring IP Services Filtering IP Packets Using Access Lists Controlling Access to a Line or Interface After you create an access list, you can apply it to one or more interfaces. Access lists can be applied on either outbound or inbound interfaces. This section describes guidelines on how to accomplish this task for both terminal lines and network interfaces. Remember the following: • When controlling access to a line, you must use a number.
Configuring IP Services Configuring the Hot Standby Router Protocol Configuring the Hot Standby Router Protocol The Hot Standby Router Protocol (HSRP) provides high network availability because it routes IP traffic from hosts on Ethernet, FDDI, or Token Ring networks without relying on the availability of any single router. HSRP is used in a group of routers for selecting an active router and a standby router.
Configuring IP Services Configuring the Hot Standby Router Protocol Note The Cisco 1000 series, Cisco 2500 series, Cisco 3000 series, Cisco 4000 series, and Cisco 4500 routers that use Lance Ethernet hardware do not support multiple Hot Standby groups on a single Ethernet interface. The Cisco 800 series, Cisco 1000 series, and Cisco 1600 series that use PQUICC Ethernet hardware do not support multiple Hot Standby groups on a single Ethernet interface.
Configuring IP Services Configuring the Hot Standby Router Protocol Configuring HSRP Group Attributes To configure other Hot Standby group attributes that affect how the local router participates in HSRP, use the following commands in interface configuration mode as needed: Command Purpose Router(config-if)# standby [group-number] timers [msec] hellotime [msec] holdtime Configures the time between hello packets and the hold time before other routers declare the active router to be down.
Configuring IP Services Configuring the Hot Standby Router Protocol Command Purpose Router(config-if)# standby mac-refresh seconds Changes the interval at which refresh packets are sent. For examples of this feature, see the section “HSRP MAC Refresh Interval Examples” at the end of this chapter. Enabling HSRP MIB Traps With Cisco IOS Release 12.0(3)T, the software supports the HSRP Management MIB feature.
Configuring IP Services Configuring the Hot Standby Router Protocol Each VPN is associated with one or more VPN routing/forwarding (VRF) instances. A VRF consists of the following elements: • IP routing table • Cisco Express Forwarding (CEF) table • Set of interfaces that use the CEF forwarding table • Set of rules and routing protocol parameters to control the information in the routing tables VPN routing information is stored in the IP routing table and the CEF table for each VRF.
Configuring IP Services Configuring the Hot Standby Router Protocol Verifying HSRP Support for MPLS VPNs The following example shows how to use show EXEC commands to verify that the HSRP virtual IP address is in the correct ARP and CEF tables: Router# show ip arp vrf vrf1 Protocol Internet Internet Address 10.2.0.1 10.2.0.20 Age (min) - Hardware Addr 00d0.bbd3.bc22 0000.0c07.ac01 Type ARPA ARPA Interface Ethernet0/2 Ethernet0/2 Router# show ip cef vrf vrf1 Prefix 0.0.0.0/0 0.0.0.0/32 10.1.0.0/16 10.
Configuring IP Services Configuring the Hot Standby Router Protocol Figure 18 Network Supporting the HSRP ICMP Redirection Filter R3 Net B e1 Net C R6 Net D Net E e1 R1 R2 e0 Active 1 Standby 2 R4 e0 Active 2 Standby 1 R5 Active 3 Standby 4 Active 4 Standby 3 Net A e0 Listen 1 R8 Default gateway: virtual IP 1 Host Net F Net G 43140 R7 If the host wants to send a packet to another host on Net D, then it first sends it to its default gateway, the virtual IP address of HSRP group 1.
Configuring IP Services Configuring the Hot Standby Router Protocol Redirects to Passive HSRP Routers Redirects to passive HSRP routers are not permitted. Redundancy may be lost if hosts learn the real IP addresses of HSRP routers. In the previous example, redirects to router R8 are not allowed because R8 is a passive HSRP router. In this case, packets from the host to Net D will first go to router R1 and then be forwarded to router R4, that is, they will traverse the network twice.
Configuring IP Services Configuring IP Accounting The IP source address of an ICMP packet must match the gateway address used by the host in the packet that triggered the ICMP packet, otherwise the host will reject the ICMP redirect packet. An HSRP router uses the destination MAC address to determine the gateway IP address of the host.
Configuring IP Services Configuring IP Accounting To configure other IP accounting functions, use the following commands in global configuration mode, as needed: Command Purpose Router(config)# ip accounting-threshold threshold Sets the maximum number of accounting entries to be created. Router(config)# ip accounting-list ip-address wildcard Filters accounting information for hosts.
Configuring IP Services Configuring TCP Performance Parameters To remove IP accounting based on the MAC address from the interface, use the no ip accounting mac-address command. Use the EXEC command show interface mac to display MAC accounting information for interfaces configured for MAC accounting. Configuring IP Precedence Accounting The precedence accounting feature provides accounting information for IP traffic based on the precedence on any interface.
Configuring IP Services Configuring TCP Performance Parameters Compressing TCP Packet Headers You can compress the headers of your TCP/IP packets in order to reduce their size, thereby increasing performance. Header compression is particularly useful on networks with a large percentage of small packets (such as those supporting many Telnet connections).
Configuring IP Services Configuring TCP Performance Parameters The CEF and fast-switching aspects of the Express TCP Header Compression feature are related to these documents: • Cisco IOS Switching Services Configuration Guide • Cisco IOS Switching Services Command Reference For information about compressing RTP headers, see the chapter “Configuring IP Multicast Routing” in this document.
Configuring IP Services Configuring TCP Performance Parameters To enable Path MTU Discovery, use the following command in global configuration mode: Command Purpose Router(config)# ip tcp path-mtu-discovery [age-timer {minutes | infinite}] Enables Path MTU Discovery. Customers using TCP connections to move bulk data between systems on distinct subnets would benefit most by enabling this feature. Customers using remote source-route bridging (RSRB) with TCP encapsulation, serial tunnel (STUN), X.
Configuring IP Services Configuring TCP Performance Parameters Enabling TCP Time Stamp The TCP time-stamp option provides better TCP round-trip time measurements. Because the time stamps are always sent and echoed in both directions and the time-stamp value in the header is always changing, TCP header compression will not compress the outgoing packet. To allow TCP header compression over a serial link, the TCP time-stamp option is disabled. Refer to RFC 1323 for more detailed information on TCP time stamp.
Configuring IP Services Configuring IP over WANs Setting the TCP Outgoing Queue Size The default TCP outgoing queue size per connection is 5 segments if the connection has a TTY associated with it (like a Telnet connection). If no TTY connection is associated with it, the default queue size is 20 segments. To change the 5-segment default value, use the following command in global configuration mode: Command Purpose Router(config)# ip tcp queuemax packets Sets the TCP outgoing queue size.
Configuring IP Services Configuring the MultiNode Load Balancing Forwarding Agent Configure the Forwarding Agent only if you are installing the MNLD Feature Set for LocalDirector. If you are installing the MNLD Feature Set for LocalDirector, refer to the MultiNode Load Balancing Feature Set for LocalDirector User Guide for information about which other hardware and software components are required.
Configuring IP Services Configuring the MultiNode Load Balancing Forwarding Agent Enabling NetFlow Switching You must enable NetFlow switching on all interfaces that will carry ContentFlow traffic. To enable NetFlow switching, use the following commands beginning in interface configuration mode: Step 1 Command Purpose Router(config-if)# interface type slot/port-adapter/port Specifies the interface, and enters interface configuration mode.
Configuring IP Services Monitoring and Maintaining the IP Network See the “Configuring IP Multicast Routing” chapter of this document for more information on how to configure IP multicast routing. Configuring the Router as a Forwarding Agent To configure the router as a Forwarding Agent, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# ip casa control-address igmp-address Specifies the IP address and IGMP address of the Forwarding Agent.
Configuring IP Services Monitoring and Maintaining the IP Network To clear caches, tables, and databases, use the following commands in EXEC mode, as needed: Command Purpose Router# clear ip accounting [checkpoint] Clears the active IP accounting or checkpointed database when IP accounting is enabled. Router# clear tcp statistics Clears TCP statistics.
Configuring IP Services IP Services Configuration Examples Command Purpose Router# show ip redirects Displays the address of the default router and the address of hosts for which an ICMP redirect message has been received. Router# show ip sockets Displays IP socket information. Router# show ip tcp header-compression Displays statistics on TCP header compression. Router# show ip traffic Displays IP protocol statistics.
Configuring IP Services IP Services Configuration Examples • Time Range Applied to an IP Access List Example • Commented IP Access List Entry Examples • IP Accounting Example • HSRP Load Sharing Example • HSRP MAC Refresh Interval Examples • HSRP MIB Trap Example • HSRP Support for MPLS VPNs Example • HSRP Support for ICMP Redirect Messages Example • MNLB Forwarding Agent Examples ICMP Services Example The following example changes some of the ICMP defaults for the first Ethernet interfac
Configuring IP Services IP Services Configuration Examples ip address 128.9.1.2 transmit-interface ethernet 1 ! interface ethernet 1 ip address 128.9.1.2 ! !use show interfaces command to find router1-MAC-address-E1 arp 128.9.1.1 router1-MAC-address-E1 arpa DRP Server Agent Example The following example enables the DRP Server Agent. Sources of DRP queries are limited by access list 1, which permits only queries from the host at address 33.45.12.4.
Configuring IP Services IP Services Configuration Examples Turbo Access Control List Example The following is a Turbo ACL configuration example. The access-list compiled global configuration command output indicates that Turbo ACL is enabled. interface Ethernet2/7 no ip address ip access-group 20 out no ip directed-broadcast shutdown ! no ip classless ip route 192.168.0.0 255.255.255.0 10.1.1.1 ! access-list compiled access-list 1 deny any access-list 2 deny 192.168.0.0 0.0.0.
Configuring IP Services IP Services Configuration Examples Extended Access List Examples In the following example, the first line permits any incoming TCP connections with destination ports greater than 1023. The second line permits incoming TCP connections to the Simple Mail Transfer Protocol (SMTP) port of host 128.88.1.2. The last line permits incoming ICMP messages for error feedback. access-list 102 permit tcp 0.0.0.0 255.255.255.255 128.88.0.0 0.0.255.255 gt 1023 access-list 102 permit tcp 0.0.0.
Configuring IP Services IP Services Configuration Examples IP Extended Access List with Fragment Control Example The first statement will match and deny only noninitial fragments destined for host 1.1.1.1. The second statement will match and permit only the remaining nonfragmented and initial fragments that are destined for host 1.1.1.1 TCP port 80. The third statement will deny all other traffic.
Configuring IP Services IP Services Configuration Examples deny tcp 171.69.0.0 0.0.255.
Configuring IP Services IP Services Configuration Examples Router A Configuration hostname RouterA ! interface ethernet 0 ip address 10.0.0.1 255.255.255.0 standby 1 ip 10.0.0.3 standby 1 priority 110 standby 1 preempt standby 2 ip 10.0.0.4 standby 2 preempt Router B Configuration hostname RouterB ! interface ethernet 0 ip address 10.0.0.2 255.255.255.0 standby 1 ip 10.0.0.3 standby 1 preempt standby 2 ip 10.0.0.
Configuring IP Services IP Services Configuration Examples HSRP MIB Trap Example The following example shows how to configure HSRP on two routers and enable the HSRP MIB trap feature. As in many environments, one router is preferred as the active one by configuring it at a higher priority level and enabling preemption. In this example, the active router is referred to as the primary router. The second router is referred to as the backup router.
Configuring IP Services IP Services Configuration Examples Router PE1 Configuration configure terminal ! ip cef ! ip vrf vrf1 rd 100:1 route-target export 100:1 route-target import 100:1 ! interface ethernet0 ip vrf forwarding vrf1 ip address 10.2.0.1 255.255.0.0 standby 1 ip 10.2.0.
Configuring IP Services IP Services Configuration Examples ip address 1.0.0.11 255.0.0.0 standby redirects standby 1 priority 100 standby 1 preempt delay minimum 20 standby 1 ip 1.0.0.1 standby 2 priority 120 standby 2 preempt delay minimum 20 standby 2 ip 1.0.0.2 MNLB Forwarding Agent Examples This section provides the following configuration examples: • Forwarding Agent Configuration for FA2 Example • Services Manager Configuration for SM Example The network configured is shown in Figure 22.
Configuring IP Services IP Services Configuration Examples service tcp-small-servers ! hostname FA2 ! ! microcode CIP flash slot0:cip26-5 microcode reload ip subnet-zero no ip domain-lookup ! ip cef distributed ip casa 206.10.20.34 224.0.1.2 forwarding-agent 1637 ! interface Ethernet0/0 ip address 172.26.56.18 255.255.255.0 no ip directed-broadcast ip route-cache flow ip igmp join-group 224.0.1.2 no ip mroute-cache ! interface Ethernet0/1 ip address 172.26.56.37 255.255.255.
Configuring IP Services IP Services Configuration Examples mtu 0 1500 mtu 1 1500 mtu 2 1500 mtu 3 1500 multiring all no secure 0 no secure 1 no secure 2 no secure 3 ping-allow 0 ping-allow 1 ping-allow 2 ping-allow 3 ip address 172.26.56.19 255.255.255.248 route 172.26.10.249 255.255.255.255 172.26.56.20 1 route 206.10.20.33 255.255.255.255 172.26.56.17 1 route 206.10.20.34 255.255.255.255 172.26.56.18 1 no rip passive failover ip address 0.0.0.0 failover password cisco telnet 161.0.0.0 255.0.0.
Configuring Server Load Balancing This chapter describes how to configure the IOS Server Load Balancing (SLB) feature. For a complete description of the SLB commands in this chapter, refer to the “Server Load Balancing Commands” chapter of the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Configuring Server Load Balancing IOS SLB Functions and Capabilities Security of the real server is provided because its address is never announced to the external network. Users are familiar only with the virtual IP address. You can filter unwanted flows based on both IP address and TCP or UDP port numbers. Though it does not eliminate the need for a firewall, IOS SLB also can help protect against some denial-of-service attacks.
Configuring Server Load Balancing IOS SLB Functions and Capabilities • SynGuard • Dynamic Feedback Protocol for IOS SLB • Alternate IP Addresses • Transparent Web Cache Balancing • NAT • Redundancy Enhancement—Stateless Backup Algorithms for Server Load Balancing IOS SLB provides two load-balancing algorithms: weighted round robin and weighted least connections.
Configuring Server Load Balancing IOS SLB Functions and Capabilities Port-Bound Servers When you define a virtual server, you must specify the TCP or UDP port handled by that virtual server. However, if you configure NAT on the server farm, you can also configure port-bound servers. Port-bound servers allow one virtual server IP address to represent one set of real servers for one service, such as HTTP, and a different set of real servers for another service, such as Telnet.
Configuring Server Load Balancing IOS SLB Functions and Capabilities Delayed Removal of TCP Connection Context Because of IP packet ordering anomalies, IOS SLB might “see” the termination of a TCP connection (a finish [FIN] or reset [RST]) followed by other packets for the connection. This problem usually occurs when there are multiple paths that the TCP connection packets can follow.
Configuring Server Load Balancing IOS SLB Functions and Capabilities Dynamic Feedback Protocol for IOS SLB The IOS SLB Dynamic Feedback Protocol (DFP) is a mechanism that allows host agents in load-balanced environments to dynamically report the change in status of the host systems that provide a virtual service. The status reported is a relative weight that specifies the capacity of a host server to perform work.
Configuring Server Load Balancing Restrictions The main disadvantage of dispatched mode is that the virtual server IP address is not modified, which means that the real servers must be Layer 2 adjacent with the load balancer or intervening routers may not be able to route to the chosen real server. NAT (directed mode) is used to solve these dispatched mode problems. IOS SLB currently supports only server NAT.
Configuring Server Load Balancing IOS SLB Configuration Task List • Does not support coordinating server load-balancing statistics among different IOS SLB instances for backup capability. • Supports FTP only in dispatched mode. • Does not support load balancing of flows between clients and real servers that are on the same LAN VLAN. • Does not support IOS SLB and Cisco Applications and Services Architecture (CASA) configured with the same virtual IP address, even if they are for different services.
Configuring Server Load Balancing IOS SLB Configuration Task List • Enabling the Real Server for Service (Required) • Specifying a Virtual Server (Required) • Associating a Virtual Server with a Server Farm (Required) • Configuring Virtual Server Attributes (Required) • Adjusting Virtual Server Values (Optional) • Preventing Advertisement of Virtual Server Address (Optional) • Enabling the Virtual Server for Service (Required) • Configuring IOS SLB Dynamic Feedback Protocol (Optional) • Co
Configuring Server Load Balancing IOS SLB Configuration Task List Specifying a Bind ID To configure a bind ID on the server farm for use by DFP, use the following command in SLB server farm configuration mode: Command Purpose Router(config-slb-sfarm)# bindid [bind_id] Specifies a bind ID on the server farm for use by DFP. Specifying a Real Server A server farm comprises a number of real servers. The real servers are the physical devices that provide the load-balanced services.
Configuring Server Load Balancing IOS SLB Configuration Task List Enabling the Real Server for Service To place the real server into service, use the following command in SLB real server configuration mode: Command Purpose Router(config-slb-real)# inservice Enables the real server for use by IOS SLB.
Configuring Server Load Balancing IOS SLB Configuration Task List Adjusting Virtual Server Values To change the default settings of the virtual server values, use the following commands in SLB virtual server configuration mode as needed: Command Purpose Router(config-slb-vserver)# client ip-address network-mask Specifies which clients are allowed to use the virtual server.
Configuring Server Load Balancing IOS SLB Configuration Task List Configuring IOS SLB Dynamic Feedback Protocol To configure IOS SLB DFP, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# ip slb dfp [password password [timeout]] Configures DFP and, optionally, sets a password and initiates SLB DFP configuration mode. Step 2 Router(config-slb-dfp)# agent ip-address port [timeout [retry-count [retry-interval]]] Configures a DFP agent.
Configuring Server Load Balancing IOS SLB Configuration Task List HSRP uses a priority scheme to determine which HSRP-configured Layer 3 switch is to be the default active Layer 3 switch. To configure a Layer 3 switch as active, you assign it a priority higher than that of all other HSRP-configured Layer 3 switches. The default priority is 100, so if you configure just one Layer 3 switch to have a higher priority, that switch becomes the default active switch.
Configuring Server Load Balancing IOS SLB Configuration Task List Step 7 Customize group attributes. See the “Customizing Group Attributes” section earlier in this chapter. Step 8 Verify the IOS SLB HSRP configuration. See the “Verifying the IOS SLB Stateless Backup Configuration” section earlier in this chapter. A sample stateless backup configuration is shown in the “IOS SLB Stateless Backup Configuration Example” section.
Configuring Server Load Balancing IOS SLB Configuration Task List VS1 VS2 TCP TCP 10.10.10.12:23 10.10.10.18:23 INSERVICE INSERVICE 2 2 Router# show ip slb vservers detail VS1, state = INSERVICE, v_index = 10 virtual = 10.10.10.12:23, TCP, service = NONE, advertise = TRUE server farm = SERVERGROUP1, delay = 10, idle = 3600 sticky timer = 0, sticky subnet = 255.255.255.
Configuring Server Load Balancing IOS SLB Configuration Task List h. Restart the connection, after waiting no longer than the sticky timeout value. i. Enter the show ip slb conns EXEC command again. j. Examine the real server connection counts again, and verify that the sticky connection is assigned to the same real server as before. Step 6 Start additional client connections. Step 7 Enter the show ip slb reals detail EXEC command. Step 8 Verify that the the connection counts are increasing.
Configuring Server Load Balancing IOS SLB Configuration Task List Troubleshooting IOS SLB Table 6 lists questions and answers that can help you troubleshoot IOS SLB. Table 6 IOS SLB Troubleshooting Guidelines Question Answer Why can I connect to real servers directly, but not Make sure that the virtual IP address is configured as a loopback in each to the virtual server? of the real servers (if you are running in dispatched mode).
Configuring Server Load Balancing Monitoring and Maintaining IOS SLB Monitoring and Maintaining IOS SLB To obtain and display run-time information about IOS SLB, use the following commands in EXEC mode as needed: Command Purpose Router# show ip slb conns [vservers virtserver-name] [client ip-address] [detail] Displays all connections handled by IOS SLB, or, optionally, only those connections associated with a particular virtual server or client.
Configuring Server Load Balancing Configuration Examples IOS SLB Network Configuration Example This section provides a configuration example based on the network layout shown in Figure 24. Figure 24 IOS SLB Network Configuration Restricted web server 10.1.1.20 Web server Web server Web server 10.1.1.1 10.1.1.2 10.1.1.3 Restricted web server 10.1.1.21 10.1.1.x Virtual server 10.0.0.1 29163 10.4.4.
Configuring Server Load Balancing Configuration Examples ip slb vservers PUBLIC_HTTP virtual 10.0.0.1 tcp www serverfarm PUBLIC inservice Unrestricted Web virtual server Handle HTTP requests Use public Web server farm ip slb vservers RESTRICTED_HTTP virtual 10.0.0.1 tcp www serverfarm RESTRICTED client 10.4.4.0 255.255.255.0 sticky 60 idle 120 group 1 inservice Restricted HTTP virtual server Handle HTTP requests Use restricted Web server farm Only allow clients from 10.4.4.
Configuring Server Load Balancing Configuration Examples • Server 4 has multiple HTTP server applications listening on ports 8080, 8081, and 8082. Servers 1 and 2 are load balanced using Switch A, which is performing server address translation. Servers 3 and 4 are load balanced using Switches B and C. These two switches are performing server address translation. These switches also perform server port translation for HTTP packets to and from Server 4.
Configuring Server Load Balancing Configuration Examples real 10.4.1.1 port 8082 inservice ! ip slb vservers HTTP2 ! Handle HTTP (port 80) requests virtual 128.4.0.1 tcp www serverfarm FARM2 inservice HSRP Configuration Example Figure 26 shows the topology of an IP network with two Layer 3 switches configured for HSRP. The following conditions exist in this network: • Device A is the active HSRP Layer 3 switch and handles packets to the real servers with IP addresses 3.0.01 through 3.0.020.
Configuring Server Load Balancing Configuration Examples Figure 26 HSRP Example Network Topology Client Virtual IP = 1.0.0.3 Fast Ethernet 1 3.0.0.1 WWW server Device A active Fast Ethernet 20 3.0.0.20 WWW server Server farm = Public HSRP group = Web_Group The configuration for Device A is as follows: hostname Device A interface GigabitEthernet 41 ip address 1.0.0.1 255.0.0.0 standby 1 ip 1.0.0.
Configuring Server Load Balancing Configuration Examples standby 1 timers 5 15 standby 1 name Web-Group interface FastEthernet 41 ip address 2.0.0.1 255.0.0.0 router eigrp 1 network 1.0.0.0 network 2.0.0.0 The standby ip interface configuration command enables HSRP and establishes 1.0.0.3 as the IP address of the virtual router. The configurations of both Layer 3 switches include this command so that both switches share the same virtual IP address. The number 1 establishes Hot Standby group 1.
Configuring Server Load Balancing Configuration Examples Cisco IOS IP Configuration Guide IPC-158
Configuring Mobile IP This chapter describes how to configure Mobile IP. For a complete description of the Mobile IP commands in this chapter, refer to the “Mobile IP Commands” chapter of the Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Configuring Mobile IP Mobile IP Overview IP routing decisions are based on the network prefix of the IP address to be scalable for the Internet. All nodes on the same link share a common network prefix. If a node moves to another link, the network prefix does not equal the network prefix on the new link. Consequently, IP routing would fail to route the packets to the node after movement to the new link. An alternative to network-prefix routing is host-specific routing.
Configuring Mobile IP How Mobile IP Works Figure 27 Mobile IP Components and Relationships Mobile node visiting foreign network Foreign network Internet Foreign agent Home agent Home network 53030 Foreign network Mobile node at home Foreign agent An MN is a node, for example, a PDA, a laptop computer, or a data-ready cellular phone, that can change its point of attachment from one network or subnet to another. This node can maintain ongoing communications while using only its home IP address.
Configuring Mobile IP How Mobile IP Works If an MN determines that it is connected to a foreign link, it acquires a care-of address. Two types of care-of addresses exist: • FA care-of address • Collocated care-of address An FA care-of address is a temporary, loaned IP address that the MN acquires from the FA agent advertisement. This type of care-of address is the exit point of the tunnel from the HA to the FA. A collocated care-of address is an address temporarily assigned to an MN interface.
Configuring Mobile IP How Mobile IP Works Figure 28 Mobile IP Typical Packet Forwarding Mobile node visiting foreign network Mobile node at home Internet Foreign agent Home agent Home network 53031 Foreign network Correspondent node Mobile IP Security Mobile IP provides the following guidelines on security between its components: • Communication between MN and HA must be authenticated. • Communication between MN and FA can optionally be authenticated.
Configuring Mobile IP How Mobile IP Works This authentication process begins when a MN sends the registration request. The MN adds the time stamp, computes the message digest, and appends the MHAE to the registration request. The HA receives the request, checks that the time stamp is valid, computes the message digest using the same key, and compares the message digest results. If the results match, the request is successfully authenticated.
Configuring Mobile IP How Mobile IP Works Storing SAs on AAA A AAA server can store a large number of SAs and scale well for future SA storage. It can accommodate not only the SAs for MN-HA authorization, but SAs for authorization between other Mobile IP components as well. Storing all SAs in a centralized location can streamline administrative and maintenance tasks related to the SAs.
Configuring Mobile IP Prerequisites For MNs on virtual networks, the active and standby HAs are peers—either HA can handle registration requests from the MN and update the mobility binding table on the peer HA. When a standby HA comes up, it must request all mobility binding information from the active HA. The active HA responds by downloading the mobility binding table to the standby HA. The standby HA acknowledges that it has received the requested binding information.
Configuring Mobile IP Mobile IP Configuration Task List Because Mobile IP requires support on the host device, each mobile node must be appropriately configured for the desired Mobile IP service with client software. Please refer to the manual entries in your mobile aware IP stack vendor documentation for details.
Configuring Mobile IP Mobile IP Configuration Task List Command Purpose Step 7 Router(config)# ip mobile host lower [upper] virtual-network net mask [aaa [load-sa]] Specifies mobile nodes (on a virtual network) and where their security associations are stored.1 Step 8 Router(config)# ip mobile host lower [upper] {interface name} Specifies mobile nodes on an interface and where their security associations are stored. Omit this step if no mobile nodes are on the interface.
Configuring Mobile IP Mobile IP Configuration Task List Command Purpose Step 1 Router(config)# aaa new-model Enables the AAA access control model. Step 2 Router(config)# aaa authorization ipmobile {tacacs+ | radius} Authorizes Mobile IP to retrieve security associations from the AAA server using TACACS+ or RADIUS. Configuring RADIUS in the Mobile IP Environment Remote Authentication Dial-in User Service (RADIUS) is a method for defining the exchange of AAA information in the network.
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List Command Purpose Router# show ip mobile globals Displays home agent and foreign agent global settings. Router# show ip mobile host group Displays mobile node groups. Router# show ip mobile secure {host | visitor | foreign-agent | home-agent | summary} address Displays security associations. Router# show ip mobile interface Displays advertisements on interfaces.
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List • Enabling HSRP (Required) • Enabling HA Redundancy for a Physical Network (Required) Depending on your network configuration, perform one of the optional tasks described in the following sections: • Enabling HA Redundancy for a Physical Network (Optional) • Enabling HA Redundancy for a Virtual Network Using One Physical Network (Optional) • Enabling HA Redundancy for a Virtual Network Using Multiple Physical Networks (Optional)
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List Enabling HA Redundancy for a Physical Network To enable HA redundancy for a physical network, use following commands beginning in interface configuration mode: Command Purpose Step 1 Router (config-if)# standby [group-number] ip ip-address Enables HSRP. Step 2 Router(config-if)# standby name hsrp-group-name Sets the name of the standby group.
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List Command Purpose Step 5 Router(config)# ip mobile home-agent standby hsrp-group-name [[virtual-network] address address] Configures the home agent for redundancy using the HSRP group to support virtual networks. Step 6 Router(config)# ip mobile secure home-agent address spi spi key hex string Sets up the home agent security association between peer routers.
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List Enabling HA Redundancy for Multiple Virtual Networks Using One Physical Network To enable HA redundancy for multiple virtual networks using one physical network, use the following commands beginning in interface configuration mode: Command Purpose Step 1 Router(config-if)# standby [group-number] ip ip-address Enables the HSRP. Step 2 Router(config-if)# standby name hsrp-group-name Sets the name of the standby group.
Configuring Mobile IP Mobile IP HA Redundancy Configuration Task List Command Purpose Router(config)# ip mobile home-agent address address Defines the global home agent address for virtual networks. In this configuration, the address is the loopback interface address. Enter this command if the mobile node and home agent are on different subnets. or or Router(config)# ip mobile home-agent Enables and controls home agent services to the router.
Configuring Mobile IP Mobile IP Configuration Examples Monitoring and Maintaining HA Redundancy To monitor and maintain HA redundancy, use the following commands in EXEC mode, as needed: Command Purpose Router# debug ip mobile standby Displays debug messages for Mobile IP redundancy activities. Router# show ip mobile globals Displays the global home address if configured. For each Mobile IP standby group, displays the home agent address supported.
Configuring Mobile IP Mobile IP Configuration Examples ! ! The next ten lines specify security associations for mobile hosts ! on virtual network 10.0.0.0 ! ip mobile secure host 10.0.0.1 spi 100 key hex 12345678123456781234567812345678 ip mobile secure host 10.0.0.2 spi 200 key hex 87654321876543218765432187654321 ip mobile secure host 10.0.0.3 spi 300 key hex 31323334353637383930313233343536 ip mobile secure host 10.0.0.4 spi 100 key hex 45678332353637383930313233343536 ip mobile secure host 10.0.0.
Configuring Mobile IP Mobile IP Configuration Examples aaa new-model aaa authorization ipmobile radius ! ip mobile home-agent ip mobile virtual-network 20.0.0.0 255.0.0.0 ip mobile host 20.0.0.1 20.0.0.3 virtual-network 20.0.0.0 255.0.0.0 aaa load-sa ! radius-server host 1.2.3.4 radius-server key cisco Foreign Agent Configuration Example In the following example, the foreign agent is providing service on Ethernet1 interface, advertising care-of address 68.0.0.
Configuring Mobile IP Mobile IP Configuration Examples Table 7 Mobile IP HA Redundancy Configuration Overview (continued) Mobile Node Home Network Physical Connections Home Agent Address Virtual network Multiple ip mobile home-agent address address In this configuration, address is the loopback interface address.
Configuring Mobile IP Mobile IP Configuration Examples Table 7 Mobile IP HA Redundancy Configuration Overview (continued) Mobile Node Home Network Physical Connections Home Agent Address Multiple virtual networks Single ip mobile virtual-network net mask address address Configuration ip mobile home-agent standby hsrp-group-name virtual-network Repeat this command for each virtual network. The address argument is an address configured on the loopback interface to be on the same subnet.
Configuring Mobile IP Mobile IP Configuration Examples Figure 30 Topology Showing HA Redundancy on a Physical Network Active HA1 1.0.0.1 Router HSRP group address Standby HA2 Physical home network 39274 1.0.0.2 Internet HA1 is favored to provide home agent service for mobile nodes on physical network e0 because the priority is set to 110, which is above the default of 100. HA1 will preempt any active home agent when it comes up.
Configuring Mobile IP Mobile IP Configuration Examples HA2 Configuration interface ethernet0 ip address 1.0.0.2 255.0.0.0 standby ip 1.0.0.10 standby name SanJoseHA ip mobile home-agent standby SanJoseHA ip mobile secure home-agent 1.0.0.1 spi 100 key hex 00112233445566778899001122334455 HA Redundancy for a Virtual Network Using One Physical Network Example This section presents two configuration examples: • The mobile node and home agent are on different subnets.
Configuring Mobile IP Mobile IP Configuration Examples Mobile Node and Home Agent on Same Subnet In this example, a loopback address is configured on the HA to be on the same subnet as the virtual network. A mobile node on a virtual network uses the HA IP address=loopback address configured for the virtual network. When a standby HA comes up, it uses this HA IP address to retrieve mobility bindings for mobile nodes on the virtual network. HA1 Configuration interface ethernet0 ip address 1.0.0.1 255.0.0.
Configuring Mobile IP Mobile IP Configuration Examples Mobile nodes are configured with a home agent address 10.0.0.10. When registrations come in, either home agent processes them (depending on routing protocols) and updates the peer home agent. The home agent that receives the registration finds the first HSRP group that is mapped to 10.0.0.10 with a peer in the group and sends the update out that interface.
Configuring Mobile IP Mobile IP Configuration Examples ip mobile secure home-agent 1.0.0.1 spi 100 key hex 00112233445566778899001122334455 ip mobile secure home-agent 2.0.0.1 spi 100 key hex 00112233445566778899001122334455 Mobile Node and Home Agent on Same Subnet In this example, a loopback address is configured on the HA to be on the same subnet as the virtual networks. A mobile node on a virtual network uses the HA IP address=loopback address configured for the virtual network.
Configuring Mobile IP Mobile IP Configuration Examples HA Redundancy for Multiple Virtual Networks Using One Physical Network Example This section presents two configuration examples: • The mobile node and home agent are on different subnets. • The mobile node and home agent are on the same subnet. Figure 31 shows an example network topology for the first scenario. Figure 32 shows an example network topology for the second scenario.
Configuring Mobile IP Mobile IP Configuration Examples Figure 32 Topology Showing HA Redundancy on Multiple Virtual Networks Using One Physical Network (Same Subnet) Active HA1 1.0.0.1 Virtual networks Router HSRP group address Loopback interface 1.0.0.2 Standby HA2 Internet Foreign agent 44138 Physical home network Mobile Node and Home Agent on Different Subnets HA1 and HA2 share responsibility for providing home agent service for mobile nodes on virtual networks 20.0.0.0 and 30.0.0.0.
Configuring Mobile IP Mobile IP Configuration Examples standby ip 1.0.0.10 standby name SanJoseHA ! specifies global HA address=HSRP group address to be used by all mobile nodes ip mobile home-agent address 1.0.0.10 ip mobile virtual-network 20.0.0.0 255.0.0.0 ip mobile virtual-network 30.0.0.0 255.0.0.0 ! used to map to the HSRP group SanJoseHA ip mobile home-agent standby SanJoseHA virtual-network ip mobile secure home-agent 1.0.0.
Configuring Mobile IP Mobile IP Configuration Examples HA Redundancy for Multiple Virtual Networks Using Multiple Physical Networks Example This section presents two configuration examples: • The mobile node and home agent are on different subnets. • The mobile node and home agent are on the same subnet. Figure 33 shows an example network topology for this configuration type.
Configuring Mobile IP Mobile IP Configuration Examples Note All routers must have identical loopback interface addresses, which will be used as the global HA address. However, do not use this address as the router ID for routing protocols. When the peer home agent receives the registration update, both home agents tunnel the packets to the mobile nodes. HA1 Configuration interface ethernet0 ip address 1.0.0.1 255.0.0.0 standby ip 1.0.0.10 standby name SanJoseHANet1 interface ethernet1 ip address 2.0.0.
Configuring Mobile IP Mobile IP Configuration Examples Mobile Node and Home Agent on Same Subnet For each virtual network, a loopback address is configured on the HA to be on the same subnet as the virtual network. It is only necessary to configure one loopback interface and assign different IP addresses to the loopback interface for each virtual network, that is, using the ip address ip-address mask [secondary] interface configuration command.
Configuring Mobile IP Mobile IP Configuration Examples ip mobile virtual-network 30.0.0.0 255.0.0.0 address 30.0.0.1 ip mobile virtual-network 40.0.0.0 255.0.0.0 address 40.0.0.1 ! used to map to the HSRP groups SanJoseHANet1 and SanJoseHANet2 ip mobile home-agent standby SanJoseHANet1 virtual-network ip mobile home-agent standby SanJoseHANet2 virtual-network ip mobile secure home-agent 1.0.0.1 spi 100 key hex 00112233445566778899001122334455 ip mobile secure home-agent 2.0.0.
IP Routing Protocols
Configuring On-Demand Routing This chapter describes how to configure On-Demand Routing (ODR). For a complete description of the ODR commands in this chapter, refer to the “On-Demand Routing Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols publication. To locate documentation of other commands in this chapter, use the command reference master index or search online. ODR is a feature that provides IP routing for stub sites, with minimum overhead.
Configuring On-Demand Routing To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the “Identifying Supported Platforms” section in the “Using Cisco IOS Software” chapter in this book. On-Demand Routing Configuration Task List To configure ODR, perform the tasks described in the following sections.
Configuring On-Demand Routing Filtering ODR Information The hub router will attempt to populate the IP routing table with ODR routes as they are learned dynamically from stub routers. The IP next hop for these routes is the IP address of the neighboring router as advertised through CDP. Use IP filtering to limit the network prefixes that the hub router will permit to be learned dynamically through ODR.
Configuring On-Demand Routing Command Purpose Step 1 Router(config)# cdp timer seconds Changes the rate at which CDP updates are sent. Step 2 Router(config)# router odr Enables ODR. Step 3 Router(config-router)# timers basic update invalid holddown flush [sleeptime] Changes the rate at which ODR routes are expired from the routing table. Other CDP features are described in the Cisco IOS Configuration Fundamentals Configuration Guide, in the “Monitoring the Router and Network” chapter.
Configuring Routing Information Protocol This chapter describes how to configure Routing Information Protocol (RIP). For a complete description of the RIP commands that appear in this chapter, refer to the “RIP Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring Routing Information Protocol RIP Configuration Task List To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the “Identifying Supported Platforms” section in the “Using Cisco IOS Software” chapter in this book.
Configuring Routing Information Protocol RIP Configuration Task List Allowing Unicast Updates for RIP Because RIP is normally a broadcast protocol, in order for RIP routing updates to reach nonbroadcast networks, you must configure the Cisco IOS software to permit this exchange of routing information. To do so, use the following command in router configuration mode: Command Purpose Router(config-router)# neighbor ip-address Defines a neighboring router with which to exchange routing information.
Configuring Routing Information Protocol RIP Configuration Task List To adjust the timers, use the following command in router configuration mode: Command Purpose Router(config-router)# timers basic update invalid holddown flush [sleeptime] Adjusts routing protocol timers. See the “Address Family Timers Example” section at the end of this chapter for examples of adjusting timers for an address family (VRF).
Configuring Routing Information Protocol RIP Configuration Task List Enabling RIP Authentication RIP Version 1 does not support authentication. If you are sending and receiving RIP Version 2 packets, you can enable RIP authentication on an interface. The key chain determines the set of keys that can be used on the interface. If a key chain is not configured, no authentication is performed on that interface, not even the default authentication.
Configuring Routing Information Protocol RIP Configuration Task List • As specifically configured, advertising a summarized local IP address pool on the specified interface (on a network access server) so that the address pool can be provided to dialup clients. Automatic summary addressing always summarizes to the classful address boundary, while the ip summary-address router configuration command summarizes addresses on a specified interface.
Configuring Routing Information Protocol RIP Configuration Task List Restrictions to RIP Route Summarization Supernet advertisement (advertising any network prefix less than its classful major network) is not allowed in RIP route summarization, other than advertising a supernet learned in the routing tables. Supernets learned on any interface that is subject to configuration are still learned. For example, the following summarization is invalid: interface E1 . . . ip summary-address rip 10.0.0.0 252.0.0.
Configuring Routing Information Protocol RIP Configuration Task List Invalid after 180 seconds, hold down 180, flushed after 240 Outgoing update filter list for all interfaces is Incoming update filter list for all interfaces is Redistributing: rip Default version control: send version 2, receive version 2 Interface Send Recv Triggered RIP Key-chain Ethernet2 2 2 Ethernet3 2 2 Ethernet4 2 2 Ethernet5 2 2 Automatic network summarization is not in effect Address Summarization: 10.11.0.
Configuring Routing Information Protocol RIP Configuration Task List Disabling the Validation of Source IP Addresses By default, the software validates the source IP address of incoming RIP routing updates. If that source address is not valid, the software discards the routing update. You might want to disable this feature if you have a router that is “off network” and you want to receive its updates. However, disabling this feature is not recommended under normal circumstances.
Configuring Routing Information Protocol RIP Configuration Task List Configuring Interpacket Delay By default, the software adds no delay between packets in a multiple-packet RIP update being sent. If you have a high-end router sending to a low-speed router, you might want to add such interpacket delay to RIP updates, in the range of 8 to 50 milliseconds.
Configuring Routing Information Protocol RIP Configuration Task List To display the contents of the RIP private database, use the following command in EXEC mode: Command Purpose Router# show ip rip database [prefix mask] Displays the contents of the RIP private database.
Configuring Routing Information Protocol RIP Configuration Task List Example 2: Incorrect Configuration The following example shows an illegal use of the ip summary-address rip router configuration command, because both addresses to be summarized have the same major network. Each route summarization on an interface must have a unique major network, whether or not the addresses have unique address masks. Router(config)# interface ethernet1 . . . Router(config-if)# ip summary-address rip 10.1.0.0 255.255.0.
Configuring Routing Information Protocol RIP Configuration Task List Disabled Split Horizon Example for Frame Relay Network Network address: 10.20.40.0 Interface address: 10.20.40.1 E0 E2 S0 Router B S2 Router C Network address: 12.13.50.0 Interface address: 12.13.50.1 Interface address: 128.125.1.1 Secondary interface address: 131.108.1.1 E1 S1 Router A Interface address: 128.125.1.2 Network address: 20.155.120.0 Interface address: 20.155.120.1 Network address: 128.125.1.
Configuring Routing Information Protocol RIP Configuration Task List Address Family Timers Example The following example shows how to adjust individual address family timers. Note that the address family “notusingtimers” will use the system defaults of 30, 180, 180, and 240 even though timer values of 5, 10, 15, and 20 are used under the general RIP configuration. Address family timers are not inherited from the general RIP configuration.
Configuring IGRP This chapter describes how to configure the Interior Gateway Routing Protocol (IGRP). For a complete description of the IGRP commands in this chapter, refer to the “IGRP Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring IGRP IGRP Configuration Task List Figure 36 Interior, System, and Exterior Routes Autonomous system 2 Autonomous system 1 Interior Subnet B System Router Router S1019a Subnet A Router Exterior IGRP Updates By default, a router running IGRP sends an update broadcast every 90 seconds. It declares a route inaccessible if it does not receive an update from the first router in the route within three update periods (270 seconds).
Configuring IGRP IGRP Configuration Task List • Disabling Holddown (Optional) • Enforcing a Maximum Network Diameter (Optional) • Validating Source IP Addresses (Optional) • Enabling or Disabling Split Horizon (Optional) Also see the examples in the “IGRP Configuration Examples” section at the end of this chapter.
Configuring IGRP IGRP Configuration Task List To control the set of interfaces with which you want to exchange routing updates, you can disable the sending of routing updates on specified interfaces by configuring the passive-interface router configuration command. See the discussion on filtering in the “Filter Routing Information” section in the “Configuring IP Routing Protocol-Independent Features” chapter.
Configuring IGRP IGRP Configuration Task List To control how traffic is distributed among multiple routes of unequal cost, use the following command in router configuration mode: Command Purpose Router(config-router)# traffic-share balanced Distribute traffic proportionately to the ratios of metrics. Adjusting the IGRP Metric Weights You have the option of altering the default behavior of IGRP routing and metric computations.
Configuring IGRP IGRP Configuration Task List To adjust the timers, use the following command in router configuration mode: Command Purpose Router(config-router)# timers basic update invalid holddown flush [sleeptime] Adjusts routing protocol timers. Disabling Holddown When the Cisco IOS software learns that a network is at a greater distance than was previously known, or it learns the network is down, the route to that network is placed in holddown.
Configuring IGRP IGRP Configuration Examples Enabling or Disabling Split Horizon Normally, routers that are connected to broadcast-type IP networks and that use distance-vector routing protocols employ the split horizon mechanism to reduce the possibility of routing loops. Split horizon blocks information about routes from being advertised by a router out of any interface from which that information originated.
Configuring IGRP IGRP Configuration Examples IGRP Feasible Successor Relationship Example In Figure 37, the assigned metrics meet the conditions required for a feasible successor relationship, so the paths in this example can be included in routing tables and be used for load balancing.
Configuring IGRP IGRP Configuration Examples Disabled Split Horizon Example Network address: 10.20.40.0 Interface address: 10.20.40.1 E0 E2 S0 Network address: 12.13.50.0 Interface address: 12.13.50.1 Router B S2 Router C Interface address: 128.125.1.1 Secondary interface address: 131.108.1.1 E1 S1 Router A Interface address: 128.125.1.2 Network address: 20.155.120.0 Interface address: 20.155.120.1 Network address: 128.125.1.0 Interface address: 131.108.1.2 Network address: 131.108.1.
Configuring IGRP IGRP Configuration Examples Cisco IOS IP Configuration Guide IPC-222
Configuring OSPF This chapter describes how to configure Open Shortest Path First (OSPF). For a complete description of the OSPF commands in this chapter, refer to the “OSPF Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring OSPF OSPF Configuration Task List • Virtual links—Virtual links are supported. • Not so stubby area (NSSA)—RFC 1587. • OSPF over demand circuit—RFC 1793. OSPF Configuration Task List OSPF typically requires coordination among many internal routers: Area Border Routers (ABRs), which are routers connected to multiple areas, and Autonomous System Boundary Routers (ASBRs).
Configuring OSPF Enabling OSPF Enabling OSPF As with other routing protocols, enabling OSPF requires that you create an OSPF routing process, specify the range of IP addresses to be associated with the routing process, and assign area IDs to be associated with that range of IP addresses. To do so, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router ospf process-id Enables OSPF routing, which places you in router configuration mode.
Configuring OSPF Configuring OSPF over Different Physical Networks Command Purpose Router(config-if)# ip ospf message-digest-key key-id md5 key Enables OSPF MD5 authentication. The values for the key-id and key arguments must match values specified for other neighbors on a network segment. Router(config-if)# ip ospf authentication [message-digest | null] Specifies the authentication type for an interface.
Configuring OSPF Configuring OSPF over Different Physical Networks To configure your OSPF network type, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip ospf network {broadcast | non-broadcast | {point-to-multipoint [non-broadcast] | point-to-point}} Configures the OSPF network type for a specified interface. See the “OSPF Point-to-Multipoint Example” section at the end of this chapter for an example of an OSPF point-to-multipoint network.
Configuring OSPF Configuring OSPF Area Parameters These parameters need only be configured in those devices that are themselves eligible to become the designated router or backup designated router (in other words, routers with a nonzero router priority value).
Configuring OSPF Configuring OSPF NSSA Stub areas are areas into which information on external routes is not sent. Instead, there is a default external route generated by the ABR, into the stub area for destinations outside the autonomous system. To take advantage of the OSPF stub area support, default routing must be used in the stub area.
Configuring OSPF Configuring Route Summarization Between OSPF Areas To control summarization and filtering of type 7 LSAs into type 5 LSAs, use the following command in router configuration mode on the ABR: Command Purpose Router(config-router)# summary address {ip-address mask | prefix mask} [not advertise] [tag tag] Controls the summarization and filtering during the translation.
Configuring OSPF Creating Virtual Links To have the software advertise one summary route for all redistributed routes covered by a network address and mask, use the following command in router configuration mode: Command Purpose Router(config-router)# summary-address {{ip-address mask} | {prefix mask}} [not-advertise][tag tag] Specifies an address and mask that covers redistributed routes, so only one summary route is advertised. Use the optional not-advertise keyword to filter out a set of routes.
Configuring OSPF Configuring Lookup of DNS Names Configuring Lookup of DNS Names You can configure OSPF to look up Domain Naming System (DNS) names for use in all OSPF show EXEC command displays. This feature makes it easier to identify a router, because the router is displayed by name rather than by its router ID or neighbor ID. To configure DNS name lookup, use the following command in global configuration mode: Command Purpose Router(config)# ip ospf name-lookup Configures DNS name lookup.
Configuring OSPF Changing the OSPF Administrative Distances Changing the OSPF Administrative Distances An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer from 0 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
Configuring OSPF Configuring OSPF over On-Demand Circuits Configuring OSPF over On-Demand Circuits The OSPF on-demand circuit is an enhancement to the OSPF protocol that allows efficient operation over on-demand circuits like ISDN, X.25 switched virtual circuits (SVCs), and dialup lines. This feature supports RFC 1793, Extending OSPF to Support Demand Circuits.
Configuring OSPF Logging Neighbors Going Up or Down Implementation Considerations Evaluate the following considerations before implementing this feature: • Because LSAs that include topology changes are flooded over an on-demand circuit, we recommend that you put demand circuits within OSPF stub areas or within NSSAs to isolate the demand circuits from as many topology changes as possible.
Configuring OSPF Changing the LSA Group Pacing OSPF LSA group pacing is enabled by default. For typical customers, the default group pacing interval for refreshing, checksumming, and aging is appropriate and you need not configure this feature. Original LSA Behavior Each OSPF LSA has an age, which indicates whether the LSA is still valid. Once the LSA reaches the maximum age (1 hour), it is discarded.
Configuring OSPF Blocking OSPF LSA Flooding Figure 40 OSPF LSAs on Individual Timers with Group Pacing and at random intervals. Individual LSA timers require many refresh packets that contain few LSAs. Individual LSA timers 20 LSAs, 1 packet 37 LSAs, 1 packet 15 LSAs, 1 packet É 10471 4 min 4 min 4 min Individual LSA timers with group pacing The group pacing interval is inversely proportional to the number of LSAs the router is refreshing, checksumming, and aging.
Configuring OSPF Reducing LSA Flooding Command Purpose Router(config-if)# ospf database-filter all out Blocks the flooding of OSPF LSA packets to the interface. On point-to-multipoint networks, to prevent flooding of OSPF LSAs, use the following command in router configuration mode: Command Purpose Router(config-router)# neighbor ip-address database-filter all out Blocks the flooding of OSPF LSA packets to the specified neighbor.
Configuring OSPF Displaying OSPF Update Packet Pacing Displaying OSPF Update Packet Pacing The former OSPF implementation for sending update packets needed to be more efficient. Some update packets were getting lost in cases where the link was slow, a neighbor could not receive the updates quickly enough, or the router was out of buffer space. For example, packets might be dropped if either of the following topologies existed: • A fast router was connected to a slower router over a point-to-point link.
Configuring OSPF Monitoring and Maintaining OSPF Monitoring and Maintaining OSPF You can display specific statistics such as the contents of IP routing tables, caches, and databases. Information provided can be used to determine resource utilization and solve network problems. You can also display information about node reachability and discover the routing path that your device packets are taking through the network.
Configuring OSPF OSPF Configuration Examples Command Purpose Router# show ip ospf neighbor [interface-name] [neighbor-id] detail Displays OSPF neighbor information on a per-interface basis. Router# show ip ospf request-list [neighbor] [interface] [interface-neighbor] Displays a list of all LSAs requested by a router. Router# show ip ospf retransmission-list [neighbor] [interface] [interface-neighbor] Displays a list of all LSAs waiting to be resent.
Configuring OSPF OSPF Configuration Examples Figure 41 OSPF Point-to-Multipoint Example Mollie 101 203 102 301 401 Platty 10.0.0.4 Jelly 402 Mollie Configuration hostname mollie ! interface serial 1 ip address 10.0.0.2 255.0.0.0 ip ospf network point-to-multipoint encapsulation frame-relay frame-relay map ip 10.0.0.1 201 broadcast frame-relay map ip 10.0.0.3 202 broadcast frame-relay map ip 10.0.0.4 203 broadcast ! router ospf 1 network 10.0.0.0 0.0.0.
Configuring OSPF OSPF Configuration Examples Jelly Configuration hostname jelly ! interface serial 2 ip address 10.0.0.3 255.0.0.0 ip ospf network point-to-multipoint encapsulation frame-relay clock rate 2000000 frame-relay map ip 10.0.0.2 301 broadcast ! router ospf 1 network 10.0.0.0 0.0.0.255 area 0 OSPF Point-to-Multipoint, Broadcast Example The following example illustrates a point-to-multipoint network with broadcast: interface Serial0 ip address 10.0.1.1 255.255.255.
Configuring OSPF OSPF Configuration Examples U - per-user static route, o - ODR Gateway of last resort is not set C 1.0.0.0/8 is directly connected, Loopback0 10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks O 10.0.1.3/32 [110/100] via 10.0.1.3, 00:39:08, Serial0 C 10.0.1.0/24 is directly connected, Serial0 O 10.0.1.5/32 [110/5] via 10.0.1.5, 00:39:08, Serial0 O 10.0.1.4/32 [110/10] via 10.0.1.
Configuring OSPF OSPF Configuration Examples In the following example, a 30-bit subnet mask is used, leaving two bits of address space reserved for serial line host addresses. There is sufficient host address space for two host endpoints on a point-to-point serial link. interface ethernet 0 ip address 131.107.1.1 255.255.255.0 ! 8 bits of host address space reserved for ethernets interface serial 0 ip address 131.107.254.1 255.255.255.
Configuring OSPF OSPF Configuration Examples Basic OSPF Configuration Example for Internal Router, ABR, and ASBRs The following example illustrates the assignment of four area IDs to four IP address ranges. In the example, OSPF routing process 109 is initialized, and four OSPF areas are defined: 10.9.50.0, 2, 3, and 0. Areas 10.9.50.0, 2, and 3 mask specific address ranges, and area 0 enables OSPF for all other networks. router ospf 109 network 131.108.20.0 0.0.0.255 area 10.9.50.0 network 131.108.0.0 0.0.
Configuring OSPF OSPF Configuration Examples Figure 42 Sample OSPF Autonomous System Network Map OSPF domain (BGP autonomous system 50000) Area 1 Router A Router B E1 E2 Interface address: 192.168.1.2 Interface address: 192.168.1.1 Network: 192.168.1.0 Interface address: E3 192.168.1.3 Router C S0 Interface address: 192.168.2.3 Network: 192.168.2.0 Area 0 S1 Interface address: 192.168.2.4 Router D E4 Interface address: 10.0.0.4 Network: 10.0.0.0 E5 Router E Interface address: 10.0.0.
Configuring OSPF OSPF Configuration Examples Note It is not necessary to include definitions of all areas in an OSPF autonomous system in the configuration of all routers in the autonomous system. You must only define the directly connected areas. In the example that follows, routes in area 0 are learned by the routers in area 1 (Router A and Router B) when the ABR (Router C) injects summary LSAs into area 1.
Configuring OSPF OSPF Configuration Examples router bgp 109 network 131.108.0.0 network 10.0.0.0 neighbor 11.0.0.6 remote-as 110 Complex OSPF Configuration for ABR Examples The following example configuration accomplishes several tasks in setting up an ABR. These tasks can be split into two general categories: • Basic OSPF configuration • Route redistribution The specific tasks outlined in this configuration are detailed briefly in the following descriptions.
Configuring OSPF OSPF Configuration Examples interface ethernet 0 ip address 192.42.110.201 255.255.255.0 ip ospf authentication-key abcdefgh ip ospf cost 10 ! interface ethernet 1 ip address 131.119.251.201 255.255.255.0 ip ospf authentication-key ijklmnop ip ospf cost 20 ip ospf retransmit-interval 10 ip ospf transmit-delay 2 ip ospf priority 4 ! interface ethernet 2 ip address 131.119.254.201 255.255.255.0 ip ospf authentication-key abcdefgh ip ospf cost 10 ! interface ethernet 3 ip address 36.56.0.
Configuring OSPF OSPF Configuration Examples The following example redistributes RIP routes with a hop count equal to 1 into OSPF. These routes will be redistributed into OSPF as external LSAs with a metric of 5, a metric type of type 1, and a tag equal to 1.
Configuring OSPF OSPF Configuration Examples route-map 1 permit match tag 3 set metric 5 ! route-map 1 deny match tag 4 ! route map 1 permit match tag 5 set metric 5 In the following configuration, a RIP learned route for network 160.89.0.0 and an ISO-IGRP learned route with prefix 49.0001.
Configuring OSPF OSPF Configuration Examples Figure 44 OSPF Administrative Distance Router C OSPF 2 External LSA 10.0.0.0 Router A Router B OSPF 1 14830 Network 10.0.0.
Configuring OSPF OSPF Configuration Examples Token Ring 0 OSPF over On-Demand Circuit BRI 0 Router A BRI 0 Ethernet 0 Router B Router A Configuration username RouterB password 7 060C1A2F47 isdn switch-type basic-5ess ip routing ! interface TokenRing0 ip address 140.10.20.7 255.255.255.0 no shut ! interface BRI0 no cdp enable description connected PBX 1485 ip address 140.10.10.7 255.255.255.0 encapsulation ppp ip ospf demand-circuit dialer map ip 140.10.10.
Configuring OSPF OSPF Configuration Examples LSA Group Pacing Example The following example changes the OSPF pacing between LSA groups to 60 seconds: router ospf timers lsa-group-pacing 60 Block LSA Flooding Example The following example prevents flooding of OSPF LSAs to broadcast, nonbroadcast, or point-to-point networks reachable through Ethernet interface 0: interface ethernet 0 ospf database-filter all out The following example prevents flooding of OSPF LSAs to point-to-multipoint networks to the nei
Configuring OSPF OSPF Configuration Examples Cisco IOS IP Configuration Guide IPC-256
Configuring EIGRP This chapter describes how to configure Enhanced Interior Gateway Routing Protocol (EIGRP). For a complete description of the EIGRP commands listed in this chapter, refer to the “EIGRP Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring EIGRP The Cisco EIGRP Implementation Note Redistribution between EIGRP and IGRP differs from normal redistribution in that the metrics of IGRP routes are compared with the metrics of external EIGRP routes. The rules of normal administrative distances are not followed, and routes with the lowest metric are selected. EIGRP offers the following features: • Fast convergence—The DUAL algorithm allows routing information to converge as quickly as any currently available routing protocol.
Configuring EIGRP EIGRP Configuration Task List convergence time. Recomputation is processor-intensive; it is advantageous to avoid unneeded recomputation. When a topology change occurs, DUAL will test for feasible successors. If there are feasible successors, it will use any it finds in order to avoid unnecessary recomputation. The protocol-dependent modules are responsible for network layer protocol-specific tasks.
Configuring EIGRP EIGRP Configuration Task List Making the Transition from IGRP to EIGRP If you have routers on your network that are configured for IGRP, and you want to make a transition to routing EIGRP, you must designate transition routers that have both IGRP and EIGRP configured. In these cases, perform the tasks as noted in the previous section, “Enabling EIGRP,” and also see the chapter “Configuring IGRP” in this document.
Configuring EIGRP EIGRP Configuration Task List To adjust the EIGRP metric weights, use the following command in router configuration mode: Command Purpose Router(config-router)# metric weights tos k1 k2 k3 k4 k5 Adjusts the EIGRP metric or K value.
Configuring EIGRP EIGRP Configuration Task List • The K-value mismatch error message can also be displayed if one of the two peers has transmitted a “goodbye” message, and the receiving router does not support this message. In this case, the receiving router will interpret this message as a K-value mismatch. The Goodbye Message The goodbye message is a feature designed to improve EIGRP network convergence.
Configuring EIGRP EIGRP Configuration Task List Command Purpose Router(config-router)# no auto-summary Disables automatic summarization. Route summarization works in conjunction with the ip summary-address eigrp interface configuration command, in which additional summarization can be performed. If automatic summarization is in effect, there usually is no need to configure network level summaries using the ip summary-address eigrp command.
Configuring EIGRP EIGRP Configuration Task List Figure 46 Floating Summary Route is Applied to Router-B 10.1.1.0/24 0.0.0.0/0 Router-A Router-C Router-B interface Serial 0/1 ip summary-address eigrp 100 0.0.0.0.0.0.0.0 25 . . . . 0.0.0.0.0.0.0.0 via (489765/170) 103615 Router-B#show ip route Router-C#show ip route . . . . 0.0.0.0.0.0.0.0 via (489765/90) The configuration of the default summary route on Router-B sends a 0.0.0.
Configuring EIGRP EIGRP Configuration Task List Figure 47 Floating Summary Route Applied for Dual-Homed Remotes 10.1.1.0/24 0.0.0.0/0 0.0.0.0/0 Router-A Router-C Router-B 0.0.0.0/0 Router-E 103614 Router-D 0.0.0.0/0 interface Serial 0/1 ip summary-address eigrp 100 0.0.0.0.0.0.0.0 250 Router-B#show ip route . . . . 0.0.0.0.0.0.0.
Configuring EIGRP EIGRP Configuration Task List Command Purpose Step 3 Router(config-if)# ip authentication key-chain eigrp autonomous-system key-chain Enables authentication of EIGRP packets. Step 4 Router(config-if)# exit Router(config)# Exits to global configuration mode. Step 5 Router(config)# key chain name-of-chain Identifies a key chain. (Match the name configured in Step 1.) Step 6 Router(config-keychain)# key number In keychain configuration mode, identifies the key number.
Configuring EIGRP EIGRP Configuration Task List By default, hello packets are sent every 5 seconds. The exception is on low-speed, nonbroadcast multiaccess (NBMA) media, where the default hello interval is 60 seconds. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. The default hello interval remains 5 seconds for high-speed NBMA networks.
Configuring EIGRP EIGRP Configuration Task List Configuring EIGRP Stub Routing The EIGRP Stub Routing feature improves network stability, reduces resource utilization, and simplifies stub router configuration. Stub routing is commonly used in a hub-and-spoke network topology. In a hub-and-spoke network, one or more end (stub) networks are connected to a remote router (the spoke) that is connected to one or more distribution routers (the hub).
Configuring EIGRP EIGRP Configuration Task List only a default route to the remote router. The EIGRP Stub Routing feature does not automatically enable summarization on the distribution router. In most cases, the network administrator will need to configure summarization on the distribution routers. Note When configuring the distribution router to send only a default route to the remote router, you must use the ip classless command on the remote router.
Configuring EIGRP EIGRP Configuration Task List Dual-homed routing can introduce instability into an EIGRP network. In Figure 50, distribution router 1 is directly connected to network 10.3.1.0/24. If summarization or filtering is applied on distribution router 1, the router will advertise network 10.3.1.0/24 to all of its directly connected EIGRP neighbors (distribution router 2 and the remote router).
Configuring EIGRP EIGRP Configuration Task List Figure 51 Dual-Homed Remote Topology with a Failed Route to a Distribution Router 10.3.1.0/24 Remote router (spoke) Distribution router 2 (hub) 46093 Distribution router 1 (hub) 10.1.1.0/24 Corporate network 10.2.1.0/24 X It is not desirable for traffic from distribution router 2 to travel through any remote router in order to reach network 10.3.1.0/24.
Configuring EIGRP Monitoring and Maintaining EIGRP EIGRP Stub Routing Configuration Task List To configure EIGRP Stub Routing, perform the tasks described in the following sections. The tasks in the first section are required; the task in the last section is optional.
Configuring EIGRP EIGRP Configuration Examples To display various routing statistics, use the following commands in EXEC mode, as needed: Command Purpose Router# show ip eigrp interfaces [interface-type | interface-number] [as-number] Displays information about interfaces configured for EIGRP. Router# show ip eigrp neighbors [interface-type | as-number | static] Displays the EIGRP discovered neighbors.
Configuring EIGRP EIGRP Configuration Examples instead, this traffic will be sent to the null 0 interface where it is dropped. The recommended way to send only the default route out a given interface is to use a distribute-list command. You can configure this command to filter all outbound route advertisements sent out the interface with the exception of the default (0.0.0.0).
Configuring EIGRP EIGRP Configuration Examples Route Authentication Example The following example enables MD5 authentication on EIGRP packets in autonomous system 1. Figure 52 shows the scenario.
Configuring EIGRP EIGRP Configuration Examples Stub Routing Example A router that is configured as a stub with the eigrp stub command shares connected and summary routing information with all neighbor routers by default. Four optional keywords can be used with the eigrp stub command to modify this behavior: • receive-only • connected • static • summary This section provides configuration examples for all forms of the eigrp stub command.
Configuring Integrated IS-IS This chapter describes how to configure Integrated Intermediate System-to-Intermediate System (IS-IS). For a complete description of the integrated IS-IS commands listed in this chapter, refer to the “Integrated IS-IS Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring Integrated IS-IS IS-IS Configuration Task List Small IS-IS networks are built as a single area that includes all the routers in the network. As the network grows larger, it is usually reorganized into a backbone area made up of the connected set of all Level 2 routers from all areas, which is in turn connected to local areas. Within a local area, routers know how to reach all system IDs.
Configuring Integrated IS-IS IS-IS Interface Parameters Configuration Task List Enabling IP Routing for an Area on an Interface To enable IP routing and specify the area for each instance of the IS-IS routing process, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# interface interface-type interface-number Enters interface configuration mode.
Configuring Integrated IS-IS IS-IS Interface Parameters Configuration Task List Configuring IS-IS Link-State Metrics You can configure a cost for a specified interface. You can configure the default-metric value for Level 1 or Level 2 routing. To configure the metric for the specified interface, use the following command in interface configuration mode: Command Purpose Router(config-if)# isis metric default-metric [level-1 | level-2] Configures the metric (or cost) for the specified interface.
Configuring Integrated IS-IS IS-IS Interface Parameters Configuration Task List Setting the Retransmission Interval You can configure the number of seconds between retransmission of IS-IS link-state packets (LSPs) for point-to-point links. To set the retransmission level, use the following command in interface configuration mode: Command Purpose Router(config-if)# isis retransmit-interval seconds Configures the number of seconds between retransmission of IS-IS LSPs for point-to-point links.
Configuring Integrated IS-IS IS-IS Interface Parameters Configuration Task List Setting the Hello Multiplier To specify the number of IS-IS hello packets a neighbor must miss before the router should declare the adjacency as down, use the following command in interface configuration command. The default value is 3. Command Purpose Router(config-if)# isis hello-multiplier multiplier [level-1 | level-2] Sets the hello multiplier.
Configuring Integrated IS-IS IS-IS Interface Parameters Configuration Task List Limiting LSP Flooding Limiting LSP flooding is important to IS-IS networks in general, and is not limited to configuring multiarea IS-IS networks. In a network with a high degree of redundancy, such as a fully meshed set of point-to-point links over a nonbroadcast multiaccess (NBMA) transport, flooding of LSPs can limit network scalability.
Configuring Integrated IS-IS Miscellaneous IS-IS Parameters Configuration Task List Miscellaneous IS-IS Parameters Configuration Task List The following tasks differ from the preceding interface-specific IS-IS tasks because they configure IS-IS itself, rather than the interface.
Configuring Integrated IS-IS Miscellaneous IS-IS Parameters Configuration Task List Configuring IS-IS Authentication Passwords You can assign passwords to areas and domains. The area authentication password is inserted in Level 1 (station router level) LSPs, and the routing domain authentication password is inserted in Level 2 (area router level) LSPs.
Configuring Integrated IS-IS Miscellaneous IS-IS Parameters Configuration Task List Unless you specify the on-startup keyword, this command sets the overload bit immediately and it remains set until the no set-overload-bit command is specified. If you specify the on-startup keyword, you must indicate whether it is set for a specified number of seconds or until BGP has converged. If BGP does not signal IS-IS that it has converged, IS-IS will turn off the overload bit after 10 minutes.
Configuring Integrated IS-IS Miscellaneous IS-IS Parameters Configuration Task List To change the LSP refresh interval or lifetime, use the appropriate command in router configuration mode: Command Purpose Router (config-router)# lsp-refresh-interval seconds Sets the LSP refresh interval. Router (config-router)# max-lsp-lifetime seconds Sets the maximum time that link-state packets (LSPs) can remain in a router’s database without being refreshed.
Configuring Integrated IS-IS Miscellaneous IS-IS Parameters Configuration Task List Other commands are available to control the delay between successive LSPs, the retransmission of the same LSA, and the retransmission of LSPs on a point-to-point interface.
Configuring Integrated IS-IS Monitoring IS-IS Area A3253-01: System Id 0000.0000.0053 0000.0000.0003 -------------Area A3253-02: System Id 0000.0000.0002 0000.0000.0053 Interface Et1 Et1 SNPA 0060.3e58.ccdb 0000.0c03.6944 State Up Up Holdtime 22 20 Type Protocol L1 IS-IS L1 IS-IS Interface Et2 Et2 SNPA 0000.0c03.6bc5 0060.3e58.
Configuring Integrated IS-IS IS-IS Configuration Examples interface serial 0 ip router isis Router C Configuration router isis net 49.0001.0000.0000.000c.00 interface ethernet 1 ip router isis interface ethernet 2 ip router isis Figure 53 IS-IS Routing E0 E0 S0 Router A Router B Router C E2 32050 E1 Multiarea IS-IS Configuration for CLNS Network Example The following example shows a multiarea IS-IS configuration with two Level 1 areas and one Level 1-2 area.
Configuring Integrated IS-IS IS-IS Configuration Examples router isis BB net 49.2222.0000.0000.0005.00 ! router isis A3253-01 net 49.0553.0001.0000.0000.0005.00 is-type level-1 ! router isis A3253-02 net 49.0553.0002.0000.0000.0005.
Configuring Integrated IS-IS IS-IS Configuration Examples Cisco IOS IP Configuration Guide IPC-292
Configuring BGP This chapter describes how to configure Border Gateway Protocol (BGP). For a complete description of the BGP commands in this chapter, refer to the “BGP Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring BGP The Cisco BGP Implementation BGP Version 4 supports classless interdomain routing (CIDR), which lets you reduce the size of your routing tables by creating aggregate routes, resulting in supernets. CIDR eliminates the concept of network classes within BGP and supports the advertising of IP prefixes. CIDR routes can be carried by Open Shortest Path First (OSPF), Enhanced IGRP (EIGRP), and Intermediate System-to-Intermediate System (ISIS)-IP, and Routing Information Protocol (RIP).
Configuring BGP Basic BGP Configuration Task List 10. Prefer the route that can be reached through the closest IGP neighbor (the lowest IGP metric). The router will prefer the shortest internal path within the autonomous system to reach the destination (the shortest path to the BGP next hop). 11. If the following conditions are all true, insert the route for this path into the IP routing table: – Both the best route and this route are external.
Configuring BGP Advanced BGP Configuration Task List • Disabling Next Hop Processing on BGP Updates (Optional) • Configuring the BGP Version (Optional) • Configuring the MED Metric (Optional) Advanced BGP Configuration Task List Advanced, optional BGP configuration tasks are described in the following sections: • Using Route Maps to Modify Updates (Optional) • Resetting eBGP Connections Immediately upon Link Failure (Optional) • Configuring Aggregate Addresses (Optional) • Disabling Automatic
Configuring BGP Configuring Basic BGP Features Configuring Basic BGP Features The tasks described in this section are for configuring basic BGP features. Enabling BGP Routing To enable BGP routing and establish a BGP routing process, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router bgp as-number Enables a BGP routing process, which places the router in router configuration mode.
Configuring BGP Configuring Basic BGP Features Managing Routing Policy Changes Routing policies for a peer include all the configurations such as route-map, distribute-list, prefix-list, and filter-list that may impact inbound or outbound routing table updates. Whenever there is a change in the routing policy, the BGP session must be soft cleared, or soft reset, for the new policy to take effect. Performing inbound reset enables the new inbound policy to take effect.
Configuring BGP Configuring Basic BGP Features A soft reset updates the routing table for inbound and outbound routing updates. Cisco IOS software Release 12.1 and later releases support soft reset without any prior configuration. This soft reset allows the dynamic exchange of route refresh requests and routing information between BGP routers, and the subsequent re-advertisement of the respective outbound routing table.
Configuring BGP Configuring Basic BGP Features Resetting a Router Using BGP Outbound Soft Reset Outbound soft resets do not require any preconfiguration. Using the soft keyword specifies that a soft reset be performed. To perform an outbound soft reset, use the following command in EXEC mode: Command Purpose Router# clear ip bgp {* | neighbor-address | peer-group-name} soft out Performs a soft reset on the connection specified in the command.
Configuring BGP Configuring Basic BGP Features Verifying BGP Soft Reset To verify whether a soft reset is successful and check information about the routing table and about BGP neighbors, perform the following steps: Step 1 Enter the show ip bgp EXEC command to display entries in the BGP routing table. The following output shows that the peer supports the route refresh capability: Router# show ip bgp BGP table version is 5, local router ID is 10.0.33.
Configuring BGP Configuring Basic BGP Features Connection state is ESTAB, I/O status: 1, unread input bytes: 0 Local host: 172.16.232.178, Local port: 179 Foreign host: 172.16.232.
Configuring BGP Configuring Basic BGP Features In most circumstances, you also will not want to redistribute your IGP into BGP. List the networks in your autonomous system with network router configuration commands and your networks will be advertised. Networks that are listed this way are referred to as local networks and have a BGP origin attribute of “IGP.” They must appear in the main IP routing table and can have any source; for example, they can be directly connected or learned via an IGP.
Configuring BGP Configuring Basic BGP Features Configuring BGP Route Filtering by Neighbor You can filter BGP advertisements in two ways: • Use autonomous system path filters, as with the ip as-path access-list global configuration command and the neighbor filter-list router configuration command • Use access or prefix lists, as with the neighbor distribute-list router configuration command. Filtering using prefix lists is described in the “Configuring BGP Filtering Using Prefix Lists” section.
Configuring BGP Configuring Basic BGP Features • More user-friendly command-line interface (CLI). The command-line interface for using access lists to filter BGP updates is difficult to understand and use because it uses the packet filtering format. • Greater flexibility Before using a prefix list in a command, you must set up a prefix list, and you may want to assign sequence numbers to the entries in the prefix list.
Configuring BGP Configuring Basic BGP Features Configuring a Prefix List Entry You can add entries to a prefix list individually. To configure an entry in a prefix list, use the following command in router configuration mode: Command Purpose Router(config-router)# ip prefix-list list-name [seq sequence-value] {deny | permit network/length} [ge ge-value] [le le-value] Creates an entry in a prefix list and assigns a sequence number to the entry.
Configuring BGP Configuring Basic BGP Features Command Purpose Router(config-router)# ip prefix-list sequence-number Enables the automatic generation of the sequence numbers of prefix list entries. The default is enable. If you disable automatic generation of sequence numbers in a prefix list, you must specify the sequence number for each entry using the sequence-value argument of the ip prefix-list global configuration command.
Configuring BGP Configuring Basic BGP Features Router# show ip prefix-list prefix-list-name [network/length] longer Displays all entries of a prefix list that are more specific than the given network and length. Router# show ip prefix-list prefix-list-name [network/length] first-match Displays the entry of a prefix list that matches the given prefix (network and length of prefix).
Configuring BGP Configuring Basic BGP Features Disabling Next Hop Processing Using a Specific Address To disable next hop processing and provide a specific address to be used instead of the next hop address, use the following command in router configuration mode: Command Purpose Router(config-router)# neighbor {ip-address | peer-group-name} next-hop-self Disables next hop processing on BGP updates to a neighbor.
Configuring BGP Configuring Basic BGP Features The configuration of this feature in conjunction with the iBGP Multipath Load Sharing feature allows you to use an outbound route map to include BGP route reflectors in the forwarding path. The BGP Next Hop Propagation feature allows you to perform the following tasks: • Bring the route reflector into the forwarding path, which can be used with the iBGP Multipath Load Sharing feature to configure load balancing.
Configuring BGP Configuring Advanced BGP Features Configuring Advanced BGP Features The tasks in this section are for configuring advanced BGP features. Using Route Maps to Modify Updates You can use a route map on a per-neighbor basis to filter updates and modify various attributes. A route map can be applied to either inbound or outbound updates. Only the routes that pass the route map are sent or accepted in updates.
Configuring BGP Configuring Advanced BGP Features To create an aggregate address in the routing table, use the following commands in router configuration mode: Command Purpose Router(config-router)# aggregate-address address mask Creates an aggregate entry in the BGP routing table. Router(config-router)# aggregate-address address mask as-set Generates autonomous system set path information. Router(config-router)# aggregate-address address-mask summary-only Advertises summary addresses only.
Configuring BGP Configuring Advanced BGP Features The communities attribute is an optional, transitive, global attribute in the numerical range from 1 to 4,294,967,200. Along with Internet community, there are a few predefined, well-known communities, as follows: • internet—Advertise this route to the Internet community. All routers belong to it. • no-export—Do not advertise this route to eBGP peers. • no-advertise—Do not advertise this route to any peer (internal or external).
Configuring BGP Configuring Advanced BGP Features Specifying the Format for the Community A BGP community is displayed in a two-part format 2 bytes long in the show ip bgp community EXEC command output, and wherever communities are displayed in the router configuration, such as router maps and community lists. In the most recent version of the RFC for BGP, a community is of the form AA:NN, where the first part is the autonomous system number and the second part is a 2-byte number.
Configuring BGP Configuring Advanced BGP Features BGP Conditional Advertisement Configuration Task List See the following section for configuration tasks for the BGP Conditional Advertisement feature. Each task in the list indicates if the task is optional or required. • Configure the route-maps that will be used in conjunction with the advertise-map and the non-exist-map. This step may include the configuration of access-lists or prefix-lists. (Required) • Configure the router to run BGP.
Configuring BGP Configuring Advanced BGP Features Inbound soft reconfiguration allowed NEXT_HOP is always this router Community attribute sent to this neighbor Condition-map old-route, Advertise-map new-route, status:Uninitialized 2 accepted prefixes consume 72 bytes Prefix advertised 7, suppressed 0, withdrawn 4 Connections established 1; dropped 0 Last reset 01:05:29, due to Soft reconfig change BGP Conditional Advertisement Troubleshooting Tips This section provides troubleshooting information for the
Configuring BGP Configuring Advanced BGP Features In order to treat the neighbors from other autonomous systems within the confederation as special eBGP peers, use the following command in router configuration mode: Command Purpose Router(config-router)# bgp confederation peers as-number [as-number] Specifies the autonomous systems that belong to the confederation.
Configuring BGP Configuring Advanced BGP Features Figure 56 Simple BGP Model with a Route Reflector Partially meshed autonomous system Routes Router A Router C External BGP speaker Routes Reflected routes S4219 Router A Router B Route reflector The internal peers of the route reflector are divided into two groups: client peers and all the other routers in the autonomous system (nonclient peers). A route reflector reflects routes between these two groups.
Configuring BGP Configuring Advanced BGP Features Figure 57 illustrates a more complex route reflector scheme. Router A is the route reflector in a cluster with routers B, C, and D. Routers E, F, and G are fully meshed, nonclient routers. When the route reflector receives an advertised route, depending on the neighbor, it takes the following actions: • A route from an external BGP speaker is advertised to all clients and nonclient peers. • A route from a nonclient peer is advertised to all clients.
Configuring BGP Configuring Advanced BGP Features To disable client-to-client route reflection, use the no bgp client-to-client reflection command in router configuration mode: Command Purpose Router(config-router)# no bgp client-to-client reflection Disables client-to-client route reflection. As the iBGP learned routes are reflected, routing information may loop. The route reflector model has the following mechanisms to avoid routing loops: • Originator ID is an optional, nontransitive BGP attribute.
Configuring BGP Configuring Advanced BGP Features Assigning Options to the Peer Group After you create a peer group, you configure the peer group with neighbor commands. By default, members of the peer group inherit all the configuration options of the peer group. Members can also be configured to override the options that do not affect outbound updates.
Configuring BGP Configuring Advanced BGP Features Command Purpose Router(config-router)# neighbor {ip-address | peer-group-name} password string Invokes MD5 authentication on a TCP connection to a BGP peer. You can enter a case-sensitive password of up to 25 characters. The string can contain any alphanumeric characters, including spaces. A password cannot be configured in the number-space-anything format. The space after the number causes problems.
Configuring BGP Configuring Advanced BGP Features Configuring MD5 Authentication for BGP Peering Sessions You can configure MD5 authentication between two BGP peers, meaning that each segment sent on the TCP connection between the peers is verified. MD5 authentication must be configured with the same password on both BGP peers; otherwise, the connection between them will not be made.
Configuring BGP Configuring Advanced BGP Features See the “BGP Peer Group Examples” at the end of this chapter for an example of enabling MD5 authentication. BGP through PIX Firewalls When configuring BGP peers with MD5 authentication that pass through a PIX firewall you must also disable the TCP random sequence number feature on the PIX firewall because this feature will prevent the BGP peers from successfully negotiating a connection.
Configuring BGP Configuring Advanced BGP Features Indicating Backdoor Routes You can indicate which networks are reachable by using a backdoor route that the border router should use. A backdoor network is treated as a local network, except that it is not advertised. To configure backdoor routes, use the network backdoor command, beginning in router configuration mode: Command Purpose Router(config-router)# network ip-address backdoor Indicates reachable networks through backdoor routes.
Configuring BGP Configuring Advanced BGP Features To adjust BGP timers for all neighbors, use the following command in router configuration mode: Command Purpose Router(config-router)# timers bgp keepalive holdtime Adjusts BGP timers for all neighbors.
Configuring BGP Configuring Advanced BGP Features Configuring the Router to Consider a Missing MED as Worst Path To configure the router to consider a path with a missing MED attribute as the worst path, use the following command in router configuration mode: Command Purpose Router(config-router)# bgp bestpath med missing-as-worst Configures the router to consider a missing MED as having a value of infinity, making the path without a MED value the least desirable path.
Configuring BGP Configuring Advanced BGP Features In this case, path 1 would be chosen if the bgp bestpath med confed router configuration command is enabled. The fourth path has a lower MED, but it is not involved in the MED comparison because there is an external autonomous system is in this path.
Configuring BGP Configuring Advanced BGP Features to advertise the status of the route to neighbors. The penalties are cumulative. When the route flaps so often that the penalty exceeds a configurable suppress limit, the router stops advertising the route to network A, regardless of how many times it flaps. Thus, the route is dampened. The penalty placed on network A is decayed until the reuse limit is reached, upon which the route is once again advertised.
Configuring BGP Configuring Advanced BGP Features To change the default values of various dampening factors, use the following command in address family or router configuration mode: Command Purpose Router(config)# bgp dampening half-life reuse suppress max-suppress [route-map map-name] Changes the default values of route dampening factors. Monitoring and Maintaining BGP Route Dampening You can monitor the flaps of all the paths that are flapping.
Configuring BGP Monitoring and Maintaining BGP Once a route is dampened, you can display BGP route dampening information, including the time remaining before the dampened routes will be unsuppressed. To display the information, use the following command in EXEC mode: Command Purpose Router# show ip bgp dampened-paths Displays the dampened routes, including the time remaining before they will be unsuppressed.
Configuring BGP BGP Configuration Examples To display various routing statistics, use the following commands in EXEC mode, as needed: Command Purpose Router# show ip bgp prefix Displays peer groups and peers not in peer groups to which the prefix has been advertised. Also displays prefix attributes such as the next hop and the local prefix. Router# show ip bgp cidr-only Displays all BGP routes that contain subnet and supernet network masks.
Configuring BGP BGP Configuration Examples • BGP Prefix List Filtering Examples • BGP Soft Reset Examples • BGP Synchronization Examples • BGP Path Filtering by Neighbor Examples • BGP Aggregate Route Examples • BGP Community with Route Maps Examples • BGP Conditional Advertisement Configuration Examples • BGP Confederation Examples • BGP Peer Group Examples • TCP MD5 Authentication for BGP Examples BGP Route Map Examples The following example shows how you can use route maps to modify
Configuring BGP BGP Configuration Examples set set set set set local-preference 25 metric 127 weight 30000 next-hop 192.92.68.24 origin igp ! access-list 1 permit 131.108.0.0 0.0.255.255 access-list 1 permit 160.89.0.0 0.0.255.255 access-list 1 permit 198.112.0.0 0.0.127.255 It is proper behavior to not accept any autonomous system path not matching the match clause of the route map. This behavior means that you will not set the metric and the Cisco IOS software will not accept the route.
Configuring BGP BGP Configuration Examples Inbound route maps could perform prefix-based matching and set various parameters of the update. Inbound prefix matching is available in addition to autonomous system path and community list matching. The following example shows how the set local-preference route-map configuration command sets the local preference of the inbound prefix 140.10.0.0/16 to 120: ! router bgp 100 network 131.108.0.0 neighbor 131.108.1.1 remote-as neighbor 131.108.1.
Configuring BGP BGP Configuration Examples neighbor 1.1.1.3 remote-as 300 neighbor 1.1.1.3 route-map set-peer-address out route-map set-peer-address permit 10 set ip next-hop peer-address Router C Configuration router bgp 300 neighbor 1.1.1.2 remote-as 200 BGP Neighbor Configuration Examples The following example shows how BGP neighbors on an autonomous system are configured to share information.
Configuring BGP BGP Configuration Examples Figure 58 Assigning Internal and External BGP Neighbors Router Router Router Router Internal BGP Router AS 109 131.108.0.0 192.31.7.0 131.108.234.2 Router 131.108.200.1 AS 167 150.136.64.19 AS 99 S1270a Router A BGP Prefix List Filtering Examples The following examples show route filtering using a single prefix list and a group of prefixes, and how to add or delete an individual entry from a prefix list.
Configuring BGP BGP Configuration Examples The following example configuration shows how to conditionally originate a default route (0.0.0.0/0) in RIP when a prefix 10.1.1.0/24 exists in the routing table: ip prefix-list cond permit 10.1.1.0/24 ! route-map default-condition permit 10 match ip address prefix-list cond ! router rip default-information originate route-map default-condition The following example shows how to configure BGP to accept routing updates from 192.1.1.
Configuring BGP BGP Configuration Examples Added or Deleted Prefix List Entries Examples You can add or delete individual entries in a prefix list if a prefix list has the following initial configuration: ip ip ip ip prefix-list prefix-list prefix-list prefix-list abc abc abc abc deny 0.0.0.0/0 le 7 deny 0.0.0.0/0 ge 25 permit 35.0.0.0/8 permit 204.70.0.0/15 The following example shows how to delete an entry from the prefix list so that 204.70.0.0 is not permitted, and add a new entry that permits 198.
Configuring BGP BGP Configuration Examples BGP Synchronization Examples The example shown in Figure 59 shows how to use the no synchronization router configuration command. In the figure, synchronization is on, and Router B does not advertise network 198.92.68.0 to Router A until an IGRP route for network 198.92.68.0 exists. If you specify the no synchronization router configuration command, Router B advertises network 198.92.68.0 as soon as possible.
Configuring BGP BGP Configuration Examples BGP Aggregate Route Examples The following examples show how you can use aggregate routes in BGP either by redistributing an aggregate route into BGP or by using the BGP Conditional Aggregate routing feature. In the following example, the redistribute static router configuration command is used to redistribute aggregate route 193.0.0.0: ip route 193.0.0.0 255.0.0.
Configuring BGP BGP Configuration Examples The second example shows how the route map named set-community is applied to the outbound updates to neighbor 171.69.232.90. All the routes that originate from autonomous system 70 have the community values 200 200 added to their already existing values. All other routes are advertised as normal. route-map bgp 200 neighbor 171.69.232.90 remote-as 100 neighbor 171.69.232.90 send-community neighbor 171.69.232.
Configuring BGP BGP Configuration Examples The next example shows how the route map named set-community is applied to the outbound updates to neighbor 171.69.232.50 and the local-as community attribute is used to filter the routes. The routes that pass access list 1 have the special community attribute value local-as. The remaining routes are advertised normally. This special community value automatically prevents the advertisement of those routes by the BGP speakers outside autonomous system 200.
Configuring BGP BGP Configuration Examples To conditionally advertise a set of routes, use the following commands in router configuration mode: ip prefix-list BLUE permit 172.16.0.0 ip prefix-list RED permit 192.168.7.0 ! route-map map1-name permit 10 match ip address prefix-list BLUE ! route-map map2-name permit 10 match ip address prefix-list RED ! router bgp 100 neighbor 10.89.2.33 remote-as 2051 neighbor 10.89.2.
Configuring BGP BGP Configuration Examples The following is a part of the configuration from the BGP speaker 200.200.200.205 from autonomous system 701 in the same example. Neighbor 171.69.232.56 is configured as a normal eBGP speaker from autonomous system 60000. The internal division of the autonomous system into multiple autonomous systems is not known to the peers external to the confederation. router bgp 701 neighbor 171.69.232.56 remote-as 60000 neighbor 200.200.200.
Configuring BGP BGP Configuration Examples neighbor 171.69.232.110 peer-group external-peers neighbor 171.69.232.110 filter-list 400 in TCP MD5 Authentication for BGP Examples The following example enables the authentication feature between this router and the BGP neighbor at 10.108.1.1. The password that must also be configured for the neighbor is bla4u00=2nkq.The remote peer must be configured before the holddown timer expires. router bgp 109 neighbor 10.108.1.
Configuring Multiprotocol BGP Extensions for IP Multicast This chapter describes the multiprotocol Border Gateway Protocol (BGP) based upon RFC 2283, Multiprotocol Extensions for BGP-4. For a complete description of the multiprotocol BGP commands in this chapter, refer to the “Multiprotocol BGP Extensions for IP Multicast Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols.
Configuring Multiprotocol BGP Extensions for IP Multicast In BGP, the only way to perform interdomain multicast routing was to use the BGP infrastructure that was in place for unicast routing. If those routers were not multicast-capable, or there were differing policies where you wanted multicast traffic to flow, multicast routing could not be supported without multiprotocol BGP.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Figure 61 Multicast BGP Environment Router B AS 200 Unicast router IMBGP Multicast router NAP Unicast router IMBGP Multicast router AS 100 Unicast route Router A 11754 Multicast route Multiprotocol BGP Configuration Task List To configure multiprotocol BGP, perform the following tasks described in the following sections. Each section in the list is identified as either required or optional.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Understanding NLRI Keywords and Address Families Multiprotocol BGP was introduced in Cisco IOS Release 11.1(20)CC and Cisco IOS Release 12.0(2)S prior to it being integrated into Cisco IOS Release 12.1. In Cisco IOS Release 11.1(20)CC and later releases and Cisco IOS Release 12.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Command Purpose Step 3 Router(config-router)# address-family ipv4 multicast Specifies the IPv4 address family type and places the router in address family configuration mode. Step 4 Router(config-router-af)# neighbor {ip-address | peer-group-name} activate Enables the neighbor to exchange prefixes for the specified family type with the local router.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Note Peer groups that are defined in router configuration mode using the neighbor peer-group command exchange only unicast address prefixes by default. To exchange other address prefix types, such as multicast, peer groups must be defined in address family configuration mode using the neighbor activate command, as shown.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Configuring Route Maps for Multiprotocol BGP Prefixes To configure a route map for multiprotocol BGP prefixes, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router bgp autonomous-system Configures a BGP routing process and places the router in router configuration mode.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List To inject prefixes from a routing protocol into multiprotocol BGP, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router bgp autonomous-system Configures a BGP routing process and places the router in router configuration mode.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List subject it to route map conditions. If you supply a route map, you can specify various match criteria options for the multiprotocol BGP routes. If the route passes the route map, then the route is redistributed into DVMRP. If there are multicast sources in other routing domains that are known via multiprotocol BGP and there are receivers in a DVMRP cloud, they will want to receive packets from those sources.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Configuring a Multiprotocol BGP Route Reflector To configure a local router as a route reflector of multiprotocol BGP prefixes, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router bgp autonomous-system Configures a BGP routing process and places the router in router configuration mode.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List To configure an aggregate address for multiprotocol BGP, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# router bgp autonomous-system Configures a BGP routing process and places the router in router configuration mode.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Step 2 Enter the show ip bgp ipv4 multicast summary EXEC command to display a summary of multicast database information: Router# show ip bgp ipv4 multicast summary BGP router identifier 10.0.33.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List • Multiprotocol BGP Peer Examples • Multiprotocol BGP Peer Group Examples • Multiprotocol BGP Network Advertisement Examples • Multiprotocol BGP Route Map Examples • Multiprotocol BGP Route Redistribute Examples • Multiprotocol BGP Route Reflector Examples • Aggregate Multiprotocol BGP Address Examples Multiprotocol BGP Peer Examples The following example shows how to use an address family to c
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Multiprotocol BGP Network Advertisement Examples The following examples show how to use an address family to inject a network number and mask into the unicast database and the multicast database: router bgp 100 address-family ipv4 unicast network 10.0.0.0 mask 255.0.0.0 router bgp 100 address-family ipv4 multicast network 10.0.0.0 mask 255.0.0.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Multiprotocol BGP Route Reflector Examples The following example shows how to use an address family to configure internal BGP peer 10.1.1.1 as a route reflector client for both unicast and multicast prefixes: router bgp 50000 address-family ipv4 unicast neighbor 10.1.1.1 activate neighbor 10.1.1.1 route-reflector-client router bgp 50000 address-family ipv4 multicast neighbor 10.1.1.1 activate neighbor 10.1.
Configuring Multiprotocol BGP Extensions for IP Multicast Multiprotocol BGP Configuration Task List Cisco IOS IP Configuration Guide IPC-362
Configuring IP Routing Protocol-Independent Features This chapter describes how to configure IP routing protocol-independent features. For a complete description of the IP routing protocol-independent commands in this chapter, refer to the “IP Routing Protocol-Independent Commands” chapter of the Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols publication. To locate documentation of other commands in this chapter, use the command reference master index, or search online.
Configuring IP Routing Protocol-Independent Features Using Variable-Length Subnet Masks Using Variable-Length Subnet Masks Enhanced IGRP (EIGRP), Intermediate System-to-Intermediate System (IS-IS) Interdomain Routing Protocol, Open Shortest Path First (OSPF), Routing Information Protocol (RIP) Version 2, and static routes support variable-length subnet masks (VLSMs).
Configuring IP Routing Protocol-Independent Features Specifying Default Routes Table 9 Dynamic Routing Protocol Default Administrative Distances (continued) Route Source Default Distance Enhanced IGRP (EIGRP) summary route 5 Exterior Border Gateway Protocol (BGP) 20 Internal EIGRP 90 IGRP 100 OSPF 110 IS-IS 115 RIP 120 EIGRP external route 170 Interior BGP 200 Unknown 255 Static routes that point to an interface will be advertised via RIP, IGRP, and other dynamic routing protocols,
Configuring IP Routing Protocol-Independent Features Changing the Maximum Number of Paths To define a static route to a network as the static default route, use the following command in global configuration mode: Command Purpose Router(config)# ip default-network network-number Specifies a default network. Understanding Gateway of Last Resort When default information is being passed along through a dynamic routing protocol, no further configuration is required.
Configuring IP Routing Protocol-Independent Features Redistributing Routing Information protocols, the number of paths is controlled by the maximum-paths router configuration command. The static route source can always install six paths. If more paths are available, the extra paths are discarded. If some installed paths are removed from the routing table, pending routes are added automatically.
Configuring IP Routing Protocol-Independent Features Redistributing Routing Information Command Purpose Router(config-route-map)# match ip address {access-list-number | access-list-name} [...access-list-number | ...access-list-name] Matches a standard access list. Router(config-route-map)# match metric metric-value Matches the specified metric.
Configuring IP Routing Protocol-Independent Features Redistributing Routing Information Command Purpose Router(config-route-map)# set metric-type internal Sets the Multi Exit Discriminator (MED) value on prefixes advertised to Exterior BGP neighbor to match the Interior Gateway Protocol (IGP) metric of the next hop. Router(config-route-map)# set tag tag-value Sets the tag value to associate with the redistributed routes.
Configuring IP Routing Protocol-Independent Features Filtering Routing Information • IGRP can automatically redistribute static routes and information from other IGRP-routed autonomous systems. IGRP assigns static routes a metric that identifies them as directly connected. IGRP does not change the metrics of routes derived from IGRP updates from other autonomous systems. • Note that any protocol can redistribute other routing protocols if a default metric is in effect.
Configuring IP Routing Protocol-Independent Features Filtering Routing Information Configuring Default Passive Interfaces In Internet service provider (ISP) and large enterprise networks, many of the distribution routers have more than 200 interfaces.
Configuring IP Routing Protocol-Independent Features Filtering Routing Information Controlling the Advertising of Routes in Routing Updates To prevent other routers from learning one or more routes, you can suppress routes from being advertised in routing updates. Suppressing routes in route updates prevents other routers from learning the interpretation of a particular device of one or more routes. You cannot specify an interface name in OSPF.
Configuring IP Routing Protocol-Independent Features Enabling Policy Routing (PBR) For example, consider a router using IGRP and RIP. Suppose you trust the IGRP-derived routing information more than the RIP-derived routing information. In this example, because the default IGRP administrative distance is lower than the default RIP administrative distance, the router uses the IGRP-derived information and ignores the RIP-derived information.
Configuring IP Routing Protocol-Independent Features Enabling Policy Routing (PBR) To define the criteria by which packets are examined to learn if they will be policy-routed, use either one or both of the following commands in route-map configuration mode. No match clause in the route map indicates all packets. Command Purpose Router(config-route-map)# match length minimum-length maximum-length Matches the Level 3 length of the packet.
Configuring IP Routing Protocol-Independent Features Enabling Policy Routing (PBR) Table 10 IP Precedence Values Number Name 0 routine 1 priority 2 immediate 3 flash 4 flash-override 5 critical 6 internet 7 network The set commands can be used with each other. They are evaluated in the order shown in the previous task table. A usable next hop implies an interface. Once the local router finds a next hop and a usable interface, it routes the packet.
Configuring IP Routing Protocol-Independent Features Enabling Policy Routing (PBR) • The directly connected next hop must be a Cisco device with CDP enabled. • It is not supported for use in conjunction with dCEF, due to the dependency of the CDP neighbor database.
Configuring IP Routing Protocol-Independent Features Managing Authentication Keys Command Purpose Router(config-if)# ip route-cache policy Enables fast switching of policy routing. Enabling Local Policy Routing Packets that are generated by the router are not normally policy routed. To enable local policy routing for such packets, indicate which route map the router should use by using the following command in global configuration mode.
Configuring IP Routing Protocol-Independent Features Monitoring and Maintaining the IP Network Command Purpose Step 4 Router(config-keychain-key)# accept-lifetime start-time {infinite | end-time | duration seconds}] Specifies the time period during which the key can be received. Step 5 Router(config-keychain-key)# send-lifetime start-time {infinite | end-time | duration seconds} Specifies the time period during which the key can be sent.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Command Purpose Router# show key chain [name-of-chain] Displays authentication key information. Router# show route-map [map-name] Displays all route maps configured or only the one specified.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Overriding Static Routes with Dynamic Protocols Example In the following example, packets for network 10.0.0.0 from Router B (where the static route is installed) will be routed through 172.18.3.4 if a route with an administrative distance less than 110 is not available. Figure 62 illustrates this example.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Assigning administrative distances is a problem unique to each network and is done in response to the greatest perceived threats to the connected network. Even when general guidelines exist, the network manager must ultimately determine a reasonable matrix of administrative distances for the network as a whole. In the following example, the distance value for IP routes learned is 90.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples RIP and IGRP Redistribution Example Consider a WAN at a university that uses RIP as an interior routing protocol. Assume that the university wants to connect its WAN to a regional network, 172.16.0.0, which uses IGRP as the routing protocol. The goal in this case is to advertise the networks in the university network to the routers on the regional network.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples RIP and EIGRP Redistribution Examples This section provides a simple RIP redistribution example and a complex redistribution example between Enhanced IGRP (EIGRP) and BGP. Simple Redistribution Example Consider a WAN at a university that uses RIP as an interior routing protocol. Assume that the university wants to connect its WAN to a regional network, 172.16.0.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples redistribute bgp 50000 OSPF Routing and Route Redistribution Examples OSPF typically requires coordination among many internal routers, ABRs, and Autonomous System Boundary Routers (ASBRs). At a minimum, OSPF-based routers can be configured with all default parameter values, with no authentication, and with interfaces assigned to areas.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples ! ! Ethernet interface 3 is in area 3: interface ethernet 3 ip address 172.18.10.5 255.255.255.0 ! ! Ethernet interface 4 is in area 0: interface ethernet 4 ip address 172.19.1.1 255.255.255.0 ! ! Ethernet interface 5 is in area 0: interface ethernet 5 ip address 10.1.0.1 255.255.0.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Figure 63 Example OSPF Autonomous System Network Map OSPF domain (BGP autonomous system 50000) Area 1 Router A Router B E1 E2 Interface address: 192.168.1.2 Interface address: 192.168.1.1 Network: 192.168.1.0 Interface address: E3 192.168.1.3 Router C S0 Interface address: 192.168.2.3 Network: 192.168.2.0 Area 0 S1 Interface address: 192.168.2.4 Router D E4 Interface address: 10.0.0.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Note It is not necessary to include definitions of all areas in an OSPF autonomous system in the configuration of all routers in the autonomous system. You must define only the directly connected areas. In the example that follows, routes in Area 0 are learned by the routers in area 1 (Router A and Router B) when the ABR (Router C) injects summary LSAs into area 1.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples router bgp 50000 network 192.168.0.0 network 10.0.0.0 neighbor 172.16.1.6 remote-as 60000 Complex OSPF Configuration Example The following example configuration accomplishes several tasks in setting up an ABR.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples interface ethernet 0 ip address 192.168.110.201 255.255.255.0 ip ospf authentication-key abcdefgh ip ospf cost 10 ! interface ethernet 1 ip address 172.19.251.201 255.255.255.0 ip ospf authentication-key ijklmnop ip ospf cost 20 ip ospf retransmit-interval 10 ip ospf transmit-delay 2 ip ospf priority 4 ! interface ethernet 2 ip address 172.19.254.201 255.255.255.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Default Metric Values Redistribution Example The following example shows a router in autonomous system 1 using both RIP and IGRP. The example advertises IGRP-derived routes using RIP and assigns the IGRP-derived routes a RIP metric of 10.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples redistribute iso-igrp nsfnet route-map 3 ! route-map 2 permit match route-type external match tag 5 set metric 5 set level level-2 ! route-map 3 permit match address 2000 set metric 30 With the following configuration, OSPF external routes with tags 1, 2, 3, and 5 are redistributed into RIP with metrics of 1, 1, 5, and 5, respectively. The OSPF routes with a tag of 4 are not redistributed.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples See more route map examples in the “BGP Route Map Examples” and “BGP Community with Route Maps Examples” sections of the 12.4 BGP documentation. Passive Interface Examples The following example configures Ethernet interface 1 as a passive interface under IGRP. Figure 65 shows the router topology. Routing updates are sent out all interfaces in the 192.168/16 network except for Ethernet interface 1.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples The passive-interface router configuration command is typically used when the wildcard specification on the network router configuration command configures more interfaces than is desirable. The following configuration causes OSPF to run on all subnets of 172.18.0.0: interface ethernet 0 ip address 172.18.1.1 255.255.255.0 interface ethernet 1 ip address 172.18.2.1 255.255.255.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples interface async 1 ip policy route-map equal-access ! route-map equal-access permit 10 match ip address 1 set ip default next-hop 172.16.6.6 route-map equal-access permit 20 match ip address 2 set ip default next-hop 192.168.7.7 route-map equal-access permit 30 set default interface null0 Key Management Examples The following example configures a key chain named trees.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples interface Fddi0 ip address 10.1.1.1 255.255.255.0 no keepalive ! interface Fddi1 ip address 172.16.1.1 255.255.255.0 ip rip send version 1 ip rip receive version 1 no keepalive ! router rip version 2 network 172.19.0.0 network 10.0.0.0 network 172.16.0.
Configuring IP Routing Protocol-Independent Features IP Routing Protocol-Independent Configuration Examples Cisco IOS IP Configuration Guide IPC-396
IP Multicast
Configuring IP Multicast Routing This chapter describes how to configure IP multicast routing. For a complete description of the IP multicast routing commands in this chapter, refer to the “IP Multicast Routing Commands” chapter of the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast. To locate documentation of other commands in this chapter, use the command reference master index, or search online.
Configuring IP Multicast Routing The Cisco IP Multicast Routing Implementation The Cisco IP Multicast Routing Implementation The Cisco IOS software supports the following protocols to implement IP multicast routing: • IGMP is used between hosts on a LAN and the routers on that LAN to track the multicast groups of which hosts are members.
Configuring IP Multicast Routing The Cisco IP Multicast Routing Implementation Multicast addresses in the range 224.0.0.0 to 224.0.0.255 are reserved for use by routing protocols and other network control traffic. The address 224.0.0.0 is guaranteed not to be assigned to any group. IGMP packets are transmitted using IP multicast group addresses as follows: • IGMP general queries are destined to the address 224.0.0.1 (all systems on a subnet).
Configuring IP Multicast Routing Basic IP Multicast Routing Configuration Task List PIM can operate in dense mode or sparse mode. It is possible for the router to handle both sparse groups and dense groups at the same time. In dense mode, a router assumes that all other routers want to forward multicast packets for a group. If a router receives a multicast packet and has no directly connected members or PIM neighbors present, a prune message is sent back to the source.
Configuring IP Multicast Routing Enabling IP Multicast Routing • Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits (Optional) • Configuring an IP Multicast Boundary (Optional) • Configuring an Intermediate IP Multicast Helper (Optional) • Storing IP Multicast Headers (Optional) • Enabling CGMP (Optional) • Configuring Stub IP Multicast Routing (Optional) • Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List (Optional) • Monitoring and Main
Configuring IP Multicast Routing Enabling PIM on an Interface Command Purpose Router(config-if)# ip pim dense-mode Enables PIM dense mode on the interface. See the “PIM Dense Mode Example” section later in this chapter for an example of how to configure a PIM interface in dense mode.
Configuring IP Multicast Routing Enabling PIM on an Interface Command Purpose Router(config-if)# ip pim sparse-dense-mode Enables PIM to operate in sparse or dense mode, depending on the group. Configuring PIM Dense Mode State Refresh If you have PIM dense mode (PIM-DM) enabled on a router interface, the PIM Dense Mode State Refresh feature is enabled by default. PIM-DM builds source-based multicast distribution trees that operate on a “flood and prune” principle.
Configuring IP Multicast Routing Configuring Auto-RP Configuring a Rendezvous Point If you configure PIM to operate in sparse mode, you must also choose one or more routers to be rendezvous points (RPs). You need not configure the routers to be RPs; they learn how to become RPs themselves. RPs are used by senders to a multicast group to announce their existence and by receivers of multicast packets to learn about new senders.
Configuring IP Multicast Routing Configuring Auto-RP Setting Up Auto-RP in a New Internetwork If you are setting up Auto-RP in a new internetwork, you do not need a default RP because you configure all the interfaces for sparse-dense mode. Follow the process described in the section “Adding Auto-RP to an Existing Sparse Mode Cloud,” except that you should omit the first step of choosing a default RP.
Configuring IP Multicast Routing Configuring Auto-RP Find a router whose connectivity is not likely to be interrupted and assign it the role of RP-mapping agent. All routers within time-to-live (TTL) number of hops from the source router receive the Auto-RP discovery messages. To assign the role of RP mapping agent in that router, use the following command in global configuration mode: Command Purpose Router(config)# ip pim send-rp-discovery scope ttl-value Assigns the RP mapping agent.
Configuring IP Multicast Routing IGMP Features Configuration Task List IGMP Features Configuration Task List To configure IGMP features, perform the tasks described in the following sections. The tasks in the first section are required; the tasks in the remaining sections are optional.
Configuring IP Multicast Routing IGMP Features Configuration Task List Changing the IGMP Version By default, the router uses IGMP Version 2 (IGMPv2), which allows such features as the IGMP query timeout and the maximum query response time. All routers on the subnet must support the same version. The router does not automatically detect Version 1 routers and switch to Version 1 as did earlier releases of the Cisco IOS software.
Configuring IP Multicast Routing IGMP Features Configuration Task List Routers That Run IGMP Version 2 IGMPv2 improved the query messaging capabilities of IGMPv1. The query and membership report messages in IGMPv2 are identical to the IGMPv1 messages with two exceptions. 1. IGMPv2 query messages are broken into two categories: general queries (identical to IGMPv1 queries) and group-specific queries. 2. IGMPv1 membership reports and IGMPv2 membership reports have different IGMP type codes.
Configuring IP Multicast Routing IGMP Features Configuration Task List IGMPv3 is the industry-designated standard protocol for hosts to signal channel subscriptions in Source Specific Multicast (SSM). For SSM to rely on IGMPv3, IGMPv3 must be available in last hop routers and host operating system network stacks, and be used by the applications running on those hosts.
Configuring IP Multicast Routing IGMP Features Configuration Task List If IGMPv3 is needed to support SSM, then you have two configuration alternatives as follows: • Configure only the interface for IGMPv2 and use IGMP v3lite and URD. • Enable IGMPv3 and accept the higher leave latencies through the CGMP switch. Changing the IGMP Query Timeout You can specify the period of time before the router takes over as the querier for the interface, after the previous querier has stopped doing so.
Configuring IP Multicast Routing IGMP Features Configuration Task List Command Purpose Router(config-if)# ip igmp static-group group-address Configures the router as a statically connected member of a group. Configuring IGMP Leave Latency In IGMPv2 and IGMPv3, hosts send IGMP messages to indicate that they do not wish to receive a particular group, source, or channel any more. The length of time between the host wanting to leave and the router stopping forwarding is called the IGMP leave latency.
Configuring IP Multicast Routing Configuring the TTL Threshold Configuring the TTL Threshold The TTL value controls whether packets are forwarded out of an interface. You specify the TTL value in hops. Only multicast packets with a TTL greater than the interface TTL threshold are forwarded on the interface. The default value is 0, which means that all multicast packets are forwarded on the interface.
Configuring IP Multicast Routing Enabling the Functional Address for IP Multicast over Token Ring LANs properties (for example, contact information, session lifetime, and the media) being used in the session (for example, audio, video, and whiteboard) with their specific attributes like TTL scope, group address, and User Datagram Protocol (UDP) port number. Many multimedia applications rely on SDP for session descriptions. However, they may use different methods to disseminate these session descriptions.
Configuring IP Multicast Routing Configuring PIM Version 2 If you configure this feature, IP multicast transmissions over Token Ring interfaces are more efficient than they formerly were. This feature reduces the load on other machines that do not participate in IP multicast because they do not process these packets. The following restrictions apply to the Token Ring functional address: • This feature can be configured only on a Token Ring interface.
Configuring IP Multicast Routing Configuring PIM Version 2 The Cisco PIM Version 2 implementation allows interoperability and transition between Version 1 and Version 2, although there might be some minor problems. You can upgrade to PIM Version 2 incrementally. PIM Versions 1 and 2 can be configured on different routers within one network. Internally, all routers on a shared media network must run the same PIM version.
Configuring IP Multicast Routing Configuring PIM Version 2 Specifying the PIM Version All systems using Cisco IOS Release 11.3(2)T or later start in PIM Version 2 mode by default. To reenable PIM Version 2 or specify PIM Version 1 for some reason, control the PIM version by using the following command in interface configuration mode: Command Purpose Router(config-if)# ip pim version [1 | 2] Configures the PIM version used.
Configuring IP Multicast Routing Configuring PIM Version 2 To prevent BSR messages from being sent or received through an interface, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip pim bsr-border Prevents BSR messages from being sent or received through an interface. To prevent Auto-RP messages from being sent or received through an interface, use the following commands beginning in global configuration mode.
Configuring IP Multicast Routing Configuring PIM Version 2 Note The Cisco IOS implementation of PIM BSR uses the value 0 as the default priority for candidate RPs and BSRs. This implementation predates the draft-ietf-pim-sm-bsr IETF draft, the first IETF draft to specify 192 as the default priority value. The Cisco IOS implementation, thus, deviates from the IETF draft. To comply with the default priority value specified in the draft, you must explicitly set the priority value to 192.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Dense Mode Dense mode groups in a mixed Version 1/Version 2 region need no special configuration; they will interoperate automatically. Sparse Mode Sparse mode groups in a mixed Version 1/Version 2 region are possible because the Auto-RP feature in Version 1 interoperates with the RP feature of Version 2.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Understanding PIM Shared Tree and Source Tree (Shortest-Path Tree) By default, members of a group receive data from senders to the group across a single data distribution tree rooted at the RP. This type of distribution tree is called shared tree, as shown in Figure 67. Data from senders is delivered to the RP for distribution to group members joined to the shared tree.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Understanding Reverse Path Forwarding Reverse Path Forwarding (RPF) is an algorithm used for forwarding multicast datagrams. It functions as follows: • If a router receives a datagram on an interface it uses to send unicast packets to the source, the packet has arrived on the RPF interface.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Assigning an RP to Multicast Groups If you have configured PIM sparse mode, you must configure a PIM RP for a multicast group. An RP can either be configured statically in each box, or learned through a dynamic mechanism. This section explains how to statically configure an RP. If the RP for a group is learned through a dynamic mechanism (such as Auto-RP), you need not perform this task for that RP.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Understanding the PIM Registering Process IP multicast sources do not use a signalling mechanism to announce their presence. Sources just send their data into the attached network, as opposed to receivers that use IGMP to announce their presence. If a source sends traffic to a multicast group configured in PIM-SM, the DR leading toward the source must inform the RP about the presence of this source.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List Limiting the Rate of PIM Register Messages To set a limit on the maximum number of PIM-SM register messages sent per second for each (S, G) routing entry, use the following global configuration command on the DR: Command Purpose Router(config)# ip pim register-rate-limit rate Sets a limit on the maximum number of PIM-SM register messages sent per second for each (S, G) routing entry.
Configuring IP Multicast Routing Advanced PIM Features Configuration Task List For traffic from DVMRP neighbors, proxy registering is always active and cannot be influenced by the ip pim dense-mode proxy-register interface configuration command. For dense mode or DVMRP regions, proxy registering allows for limited interoperability between a dense mode region and a sparse mode domain. This limitation is referred to as “receiver must also be sender.
Configuring IP Multicast Routing Configuring an IP Multicast Static Route Configuring an IP Multicast Static Route IP multicast static routes (mroutes) allow you to have multicast paths diverge from the unicast paths. When using PIM, the router expects to receive packets on the same interface where it sends unicast packets back to the source. This expectation is beneficial if your multicast and unicast topologies are congruent.
Configuring IP Multicast Routing Controlling the Transmission Rate to a Multicast Group A multicast static route allows you to use the configuration in Figure 68 by configuring a static multicast source. The Cisco IOS software uses the configuration information instead of the unicast routing table. Therefore, multicast packets can use the tunnel without having unicast packets use the tunnel.
Configuring IP Multicast Routing Configuring RTP Header Compression Figure 70 RTP Header Compression Before RTP header compression: 20 bytes IP 8 bytes 12 bytes UDP RTP Header Payload 20 to 160 bytes After RTP header compression: 3 to 5 bytes IP/UDP/RTP header 20 to 160 bytes S5925 Payload The RTP header compression feature compresses the IP/UDP/RTP header in an RTP data packet from 40 bytes to approximately 2 to 5 bytes, as shown in Figure 70.
Configuring IP Multicast Routing Configuring RTP Header Compression Enabling RTP Header Compression on a Serial Interface To enable RTP header compression for serial encapsulation HDLC or PPP, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip rtp header-compression [passive] Enables RTP header compression. If you include the passive keyword, the software compresses outgoing RTP packets only if incoming RTP packets on the same interface are compressed.
Configuring IP Multicast Routing Configuring RTP Header Compression By default, for PPP or HDLC encapsulation, the software allows 32 RTP header compression connections (16 calls). This default can be increased to a maximum of 1000 RTP header compression connections on an interface.
Configuring IP Multicast Routing Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits In order for the Express RTP Header Compression feature to work, the following conditions must exist: • CEF switching or fast switching must be enabled on the interface. • HDLC, PPP, or Frame Relay encapsulation must be configured. • RTP header compression must be enabled.
Configuring IP Multicast Routing Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits Figure 71 Environment for IP Multicast over ATM Point-to-Multipoint VCs Source Router A Router C Router B Multiaccess WAN Router D Router E Receiver Receiver 43280 Leaf With the advent of IP multicast, where high-rate multicast traffic can occur, that approach does not scale. Furthermore, in the preceding example, routers B and C would get data traffic they do not need.
Configuring IP Multicast Routing Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits You must have ATM configured for multipoint signalling. Refer to the “Configuring ATM” chapter in the Cisco IOS Wide-Area Networking Configuration Guide for more information on how to configure ATM for point-to-multipoint signalling. You also must have IP multicast routing and PIM sparse mode configured. This feature does not work with PIM dense mode.
Configuring IP Multicast Routing Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits Idling Policy An idling policy uses the ip pim vc-count number interface configuration command to limit the number of VCs created by PIM. When the router stays at or below this number value, no idling policy is in effect. When the next VC to be opened will exceed the number value, an idling policy is exercised.
Configuring IP Multicast Routing Configuring an IP Multicast Boundary Configuring an IP Multicast Boundary You can set up an administratively scoped boundary on an interface for multicast group addresses. A standard access list defines the range of addresses affected. When a boundary is set up, no multicast data packets are allowed to flow across the boundary from either direction. The boundary allows the same multicast group address to be reused in different administrative domains.
Configuring IP Multicast Routing Storing IP Multicast Headers To configure an intermediate IP multicast helper, the first hop router and the last hop router must be configured. To configure the first hop router, use the following commands beginning in global configuration mode: Command Purpose Step 1 Router(config)# interface type number Specifies an interface.
Configuring IP Multicast Routing Enabling CGMP To allocate a circular buffer to store IP multicast packet headers that the router receives, use the following command in global configuration mode: Command Purpose Router(config)# ip multicast cache-headers Allocates a buffer to store IP multicast packet headers. Note The ip multicast cache-headers global configuration command allocates a circular buffer of approximately 32 KB. Use the show ip mpacket EXEC command to display the buffer.
Configuring IP Multicast Routing Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List Stub IP multicast routing allows stub sites to be configured quickly and easily for basic multicast connectivity, without the flooding of multicast packets and subsequent group pruning that occurs in dense mode, and without excessive administrative burden at the central site.
Configuring IP Multicast Routing Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List Enabling Native Load Splitting If two or more equal-cost paths from a source are available, unicast traffic will be load split across those paths. However, by default multicast traffic will not be load split across multiple equal-cost paths. In general, multicast traffic will flow down from the RPF neighbor.
Configuring IP Multicast Routing Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List If a tunnel is configured between Router A and Router B, and multicast traffic is made to reverse path forward over the tunnel, then the multicast packets are sent encapsulated into the tunnel as unicast packets between Router A and Router B. The underlying unicast mechanism will then perform load splitting across the equal-cost links.
Configuring IP Multicast Routing Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List Configuring Both Routers to RPF Because the use of the tunnel makes the multicast topology incongruent with the unicast topology, and only multicast traffic traverses the tunnel, you must configure the routers to reverse path forward correctly over the tunnel.
Configuring IP Multicast Routing Monitoring and Maintaining IP Multicast Routing Configuration Task List Verifying the Load Splitting Load splitting works for both fast switching and process switching, but splitting the traffic among the physical interfaces is performed differently for each case. Fast switching occurs if both the incoming and outgoing interfaces are configured with the ip mroute-cache interface configuration command. IP multicast fast switching is enabled by default.
Configuring IP Multicast Routing Monitoring and Maintaining IP Multicast Routing Configuration Task List Clearing Caches, Tables, and Databases You can remove all contents of a particular cache, table, or database. Clearing a cache, table, or database can become necessary when the contents of the particular structure have become, or are suspected to be, invalid.
Configuring IP Multicast Routing Monitoring and Maintaining IP Multicast Routing Configuration Task List Command Purpose Router# show ip pim neighbor [type number] Lists the PIM neighbors discovered by the router. Router# show ip pim rp [mapping | metric] [rp-address] Displays the RP routers associated with a sparse mode multicast group. Router# show ip pim vc [group-address | name] [type number] Displays ATM VC status information for multipoint VCs opened by PIM.
Configuring IP Multicast Routing IP Multicast Configuration Examples IP Multicast Configuration Examples This section provides the following IP multicast routing configuration examples: • PIM Dense Mode Example • PIM Sparse Mode Example • PIM Dense Mode State Refresh Example • Functional Address for IP Multicast over Token Ring LAN Example • PIM Version 2 Examples • RTP Header Compression Examples • IP Multicast over ATM Point-to-Multipoint VC Example • Administratively Scoped Boundary Examp
Configuring IP Multicast Routing IP Multicast Configuration Examples PIM Dense Mode State Refresh Example The following example shows a PIM router that is originating, processing, and forwarding PIM Dense Mode State Refresh control messages on Fast Ethernet interface 0/1 every 60 seconds: ip multicast-routing interface FastEthernet0/1 ip address 172.16.8.1 255.255.255.
Configuring IP Multicast Routing IP Multicast Configuration Examples ip pim sparse-dense-mode ! router ospf 1 network 172.21.24.8 0.0.0.7 area 1 network 172.21.24.16 0.0.0.7 area 1 ! ip pim bsr-candidate Ethernet2 30 10 ip pim rp-candidate Ethernet2 group-list 5 access-list 5 permit 239.255.2.0 0.0.0.255 Border Router Configuration Example The following example shows how to configure a border router in a PIM-SM domain on Ethernet interface 1.
Configuring IP Multicast Routing IP Multicast Configuration Examples Inconsistent candidate RP selection between Cisco and non-Cisco RFC 2362-compliant routers in the same domain if multiple candidate RPs with partially overlapping group address ranges are configured can occur. Inconsistent candidate RP selection can lead to disconnectivity between sources and receivers in the PIM domain.
Configuring IP Multicast Routing IP Multicast Configuration Examples no keepalive clockrate 64000 frame-relay map ip 1.0.0.1 17 broadcast rtp header-compression connections 64 frame-relay ip rtp header-compression frame-relay ip rtp compression-connections 32 Express RTP Header Compression with PPP Encapsulation Example The following example shows how to configure a Cisco 7200 router with the Express RTP Header Compression and PPP encapsulation: version 12.
Configuring IP Multicast Routing IP Multicast Configuration Examples no ip route-cache shutdown clockrate 2015232 ! ip default-gateway 9.1.72.1 ip classless ip route 0.0.0.0 0.0.0.0 9.1.72.1 ! router igrp 1 network 15.0.0.
Configuring IP Multicast Routing IP Multicast Configuration Examples ! interface Serial4/0 ip address 15.3.0.1 255.255.255.0 encapsulation frame-relay frame-relay map ip 15.3.0.
Configuring IP Multicast Routing IP Multicast Configuration Examples atm nsap-address 47.00918100000000410B0A1981.333333333333.00 atm pvc 1 0 5 qsaal atm pvc 2 0 16 ilmi atm multipoint-signalling map-group mpvc router ospf 9 network 171.69.214.0 0.0.0.255 area 0 ! ip classless ip pim rp-address 171.69.10.13 98 ! map-list mpvc ip 171.69.214.41 atm-nsap 47.00918100000000410B0A1981.111111111111.00 broadcast ip 171.69.214.42 atm-nsap 47.00918100000000410B0A1981.222222222222.00 broadcast ip 171.69.214.
Configuring IP Multicast Routing IP Multicast Configuration Examples The configurations for Router A and Router C are as follows: Router A—First Hop Router Configuration interface ethernet 0 ip directed-broadcast ip multicast helper-map broadcast 224.5.5.5 120 ip pim dense-mode ! access-list 120 permit udp any any eq 4000 access-list 120 deny udp any any ip forward-protocol udp 4000 Router C—Last Hop Router Configuration interface ethernet 2 ip directed-broadcast ip multicast helper-map 224.5.5.5 178.21.
Configuring IP Multicast Routing IP Multicast Configuration Examples Router B Configuration ip multicast-routing ip pim dense-mode : or ip pim sparse-mode ip pim neighbor-filter 1 access-list 1 deny 10.0.0.1 Load Splitting IP Multicast Traffic Across Equal-Cost Paths Example The following example shows how to configure a GRE tunnel between Router A and Router B. Figure 75 illustrates the tunneled topology. The configurations follow the figure.
Configuring IP Multicast Routing IP Multicast Configuration Examples ip address 100.1.3.3 255.255.255.0 bandwidth 125 clock rate 125000 IP Multicast Heartbeat Example The following example shows how to monitor IP multicast packets forwarded through this router to group address 244.1.1.1. If no packet for this group is received in a 10-second interval, an SNMP trap will be sent to the SNMP management station with the IP address of 224.1.0.1. ! ip multicast-routing ! snmp-server host 224.1.0.
Configuring Source Specific Multicast This chapter describes how to configure Source Specific Multicast (SSM). For a complete description of the SSM commands in this chapter, refer to the “IP Multicast Routing Commands” chapter of the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring Source Specific Multicast How SSM Differs from Internet Standard Multicast deploy receiver applications that are not yet SSM enabled (through support for IGMPv3). IGMPv3, IGMP v3lite, and URD interoperate with each other, so that both IGMP v3lite and URD can easily be used as transitional solutions toward full IGMPv3 support in hosts.
Configuring Source Specific Multicast IGMPv3 Host Signalling If SSM is deployed in a network already configured for PIM-SM (Cisco IOS Release 12.0 or later releases is recommended), then only the last hop routers must be upgraded to a Cisco IOS software image that supports SSM. Routers that are not directly connected to receivers do not have to upgrade to a Cisco IOS software image that supports SSM.
Configuring Source Specific Multicast URD Host Signalling Applications must be compiled with the Host Side IGMP Library (HSIL) for IGMP v3lite. This software provides applications with a subset of the IGMPv3 applications programming interface (API) that is required to write SSM applications. HSIL was developed for Cisco by Talarian and is available from the following web page: http://www.talarianmulticast.com/cgi-bin/igmpdownld One part of the HSIL is a client library linked to the SSM application.
Configuring Source Specific Multicast URD Host Signalling When the browser of a host encounters a URD intercept URL, it will try to open a TCP connection to the web server on port 465. If the last hop router is enabled for URD on the interface where the router receives the TCP packets from the host, it will intercept all packets for TCP connections destined to port 465 independent of the actual destination address of the TCP connection (independent of the address of the web server).
Configuring Source Specific Multicast Benefits Because the router returns a Content-Type of text and HTML, the best way to include the URD intercept URL into a web page is to use a frame. By defining the size of the frame, you can also hide the URD intercept URL on the displayed page. By default, URD is disabled on all interfaces. When URD is configured through the ip urd interface configuration command on an interface, it will be active only for IP multicast addresses in the SSM range.
Configuring Source Specific Multicast Restrictions deployment. Another factor that contributes to the ease of installation of SSM is the fact that it can leverage preexisting PIM-SM networks and requires only the upgrade of last hop routers to support IGMPv3, IGMP v3lite, or URD.
Configuring Source Specific Multicast Restrictions receivers will receive all (S, G) channel traffic (and filter out the unwanted traffic on input). Because of the ability of SSM to reuse the group addresses in the SSM range for many independent applications, this situation can lead to less than expected traffic filtering in a switched network.
Configuring Source Specific Multicast SSM Configuration Task List compiled with the HSIL will then dynamically bind to the newest version of the HSIL, which should support the check for IGMPv3 in the operating system kernel. Upgrading the HSIL can be done independently of upgrading the application itself. SSM Configuration Task List To configure SSM, perform the tasks described in the following sections. The tasks in the first section are required; the tasks in the remaining section are optional.
Configuring Source Specific Multicast SSM Configuration Examples SSM Configuration Examples This section provides the following SSM configuration examples: • SSM with IGMPv3 Example • SSM with IGMP v3lite and URD Example • SSM Filtering Example SSM with IGMPv3 Example The following example shows how to configure a router (running IGMPv3) for SSM: ip multicast-routing ! interface Ethernet3/1 ip address 172.21.200.203 255.255.255.
Configuring Source Specific Multicast SSM Configuration Examples ip pim accept-register list no-ssm-range ip access-list extended msdp-nono-list deny ip any 232.0.0.0 0.255.255.255 ! SSM Range ! . ! . ! . ! See ftp://ftpeng.cisco.com/ipmulticast/config-notes/msdp-sa-filter.txt for other SA ! messages that typically need to be filtered. permit ip any any ! Filter generated SA messages in SSM range. This configuration is only needed if there ! are directly connected sources to this router.
Configuring Source Specific Multicast SSM Configuration Examples Cisco IOS IP Configuration Guide IPC-470
Configuring Bidirectional PIM This chapter describes how to configure the Bidirectional PIM (bidir-PIM) feature. Bidir-PIM is a variant of the Protocol Independent Multicast (PIM) suite of routing protocols for IP multicast and is an extension of the existing PIM sparse mode (PIM-SM) feature. Bidir-PIM resolves some limitations of PIM-SM for groups with a large number of sources. Bidir-PIM is based on the draft-kouvelas-pim-bidir-new-00.txt Internet Engineering Task Force (IETF) protocol specification.
Configuring Bidirectional PIM Bidir-PIM Overview Membership to a bidirectional group is signalled via explicit join messages. Traffic from sources is unconditionally sent up the shared tree toward the RP and passed down the tree toward the receivers on each branch of the tree. Bidir-PIM is designed to be used for many-to-many applications within individual PIM domains. Multicast groups in bidirectional mode can scale to an arbitrary number of sources without incurring overhead due to the number of sources.
Configuring Bidirectional PIM Bidir-PIM Overview Figure 77 Bidirectional Shared Tree RP (*, G) (*, G) (*, G) Receiver Receiver Source 33354 (*, G) (*, G) When packets are forwarded downstream from the RP toward receivers, there are no fundamental differences between bidir-PIM and PIM-SM. Bidir-PIM deviates substantially from PIM-SM when passing traffic from sources upstream toward the RP.
Configuring Bidirectional PIM Bidir-PIM Configuration Task List Bidirectional Group Tree Building The procedure for joining the shared tree of a bidirectional group is almost identical to that used in PIM SM. One main difference is that, for bidirectional groups, the role of the DR is assumed by the DF for the RP.
Configuring Bidirectional PIM Bidir-PIM Configuration Task List Configuring Bidir-PIM Most of the configuration requirements for bidir-PIM are the same as those for configuring PIM-SM. You need not enable or disable an interface for carrying traffic for multicast groups in bidirectional mode. Instead, you configure which multicast groups you want to operate in bidirectional mode.
Configuring Bidirectional PIM Bidir-PIM Configuration Example Monitoring and Maintaining Bidir-PIM To display bidir-PIM information, use the following commands in EXEC mode, as needed: Command Purpose Router# show ip pim interface [type number] [df | count] [rp-address] Displays information about the elected DF for each RP of an interface, along with the unicast routing metric associated with the DF.
Configuring Multicast Source Discovery Protocol This chapter describes the Multicast Source Discovery Protocol (MSDP) feature. For a complete description of the MSDP commands in this chapter, refer to the “Multicast Source Discovery Protocol Commands” chapter of the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast publication. To locate documentation of other commands in this chapter, use the command reference master index, or search online.
Configuring Multicast Source Discovery Protocol How MSDP Works and the address or the originator ID of the RP, if configured. If the peer is an RP and has a member of that multicast group, the data packet is decapsulated and forwarded down the shared-tree in the remote domain. The PIM designated router (DR) directly connected to the source sends the data encapsulated in a PIM register message to the RP in the domain.
Configuring Multicast Source Discovery Protocol Benefits Benefits MSDP has the following benefits: • It breaks up the shared multicast distribution tree. You can make the shared tree local to your domain. Your local members join the local tree, and join messages for the shared tree never need to leave your domain. • PIM-SM domains can rely on their own RPs only, thus decreasing reliance on RPs in another domain.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List Configuring an MSDP Peer You enable MSDP by configuring an MSDP peer to the local router. Note The router you specify by Domain Naming System (DNS) name or IP address as an MSDP peer is probably a Border Gateway Protocol (BGP) neighbor. If it is not, see the section “Configuring a Default MSDP Peer” later in this document. To configure an MSDP peer, use the following commands in global configuration mode as needed.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List Requesting Source Information from an MSDP Peer Local RPs can send SA requests and get immediate response for all active sources for a given group. By default, the router does not send any SA request messages to its MSDP peers when a new member joins a group and wants to receive multicast traffic. The new member just waits to receive the next periodic SA message.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List To further restrict which registered sources are advertised, use the following command in global configuration mode. The access list or autonomous system path access list determines which (S, G) pairs are advertised. Command Purpose Router(config)# ip msdp redistribute [list access-list] [asn as-access-list] [route-map map-name] Advertises (S, G) pairs that pass the access list or route map to other domains.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List To apply an MSDP filter, use the following commands in global configuration mode as needed: Command Purpose Router(config)# ip msdp sa-filter out {peer-address | peer-name} Filters all SA messages to the specified MSDP peer. Router(config)# ip msdp sa-filter out {peer--address | peer-name} list access-list To the specified MSDP peer, passes only those SA messages that pass the extended access list.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List Configuring a Default MSDP Peer An MSDP peer of the local router is probably a BGP peer also. However, if you do not want to have or cannot have a BGP peer, you could define a default MSDP peer from which to accept all SA messages. The default MSDP peer must be a previously configured MSDP peer. Configure a default MSDP peer when you are not BGP- or multiprotocol BGP-peering with an MSDP peer.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List If you specify a prefix list, the peer will be a default peer only for the prefixes in the list. You can have multiple active default peers when you have a prefix list associated with each. When you do not have any prefix lists, you can configure multiple default peers, but only the first one is the active default peer as long as the router has connectivity to this peer and the peer is alive.
Configuring Multicast Source Discovery Protocol MSDP Configuration Task List Including a Bordering PIM Dense Mode Region in MSDP You might have a router that borders a PIM-SM region with a dense mode region. By default, sources in the dense mode region are not included in MSDP. You could configure this border router to send SA messages for sources active in the dense mode region.
Configuring Multicast Source Discovery Protocol Monitoring and Maintaining MSDP Monitoring and Maintaining MSDP To monitor MSDP SA messages, peers, state, or peer status, use the following commands in EXEC mode as needed: Command Purpose Router# debug ip msdp [peer-address | peer-name] [detail] [routes] Debugs an MSDP activity. Router# debug ip msdp resets Debugs MSDP peer reset reasons.
Configuring Multicast Source Discovery Protocol MSDP Configuration Examples MSDP Configuration Examples This section contains the following MSDP configurations examples: • Default MSDP Peer • Logical RP Default MSDP Peer The following example is a partial configuration of Router A and Router C in Figure 79. Each of these ISPs may have more than one customer like the customer in Figure 79 that use default peering (no BGP or MBGP). In that case, they may have similar configurations.
Configuring Multicast Source Discovery Protocol MSDP Configuration Examples Figure 80 Logical RP Using MSDP Domain 2 Router F Domain 1 192.169.1.x Router E .6 Loopback 0 Receiver 192.168.1.6 Router B Loopback 10 Loopback 0 10.10.10.10 192.168.1.2 e1/2/.2 Router C Loopback 10 10.10.10.10 Loopback 0 10.10.10.10 171.69.2.x e3/0/2/.4 Loopback 0 192.168.1.4 192.168.1.3 e3/.3 Router D Loopback 10 10.10.10.10 (Host) Sender e3/0/1/.5 Loopback 0 192.168.1.
Configuring Multicast Source Discovery Protocol MSDP Configuration Examples ip address 171.69.2.2 255.255.255.0 ip pim sparse-dense-mode no shutdown ! interface Ethernet4/0/0 description LANethernet3 ip address 171.69.3.2 255.255.255.0 ip pim sparse-dense-mode no shutdown ! router ospf 10 network 171.69.0.0 0.0.255.255 area 0 network 10.10.10.10 0.0.0.0 area 0 network 192.168.1.2 0.0.0.0 area 0 ! router bgp 1 no synchronization network 171.69.0.0 nlri unicast multicast network 192.168.1.2 mask 255.255.255.
Configuring Multicast Source Discovery Protocol MSDP Configuration Examples no shutdown ! interface Loopback10 ip address 10.10.10.10 255.255.255.255 ip pim sparse-dense-mode no shutdown ! interface Ethernet2 description LANethernet 0 ip address 171.69.0.3 255.255.255.0 ip pim sparse-dense-mode no shutdown ! interface Ethernet3 description LANethernet 2 ip address 171.69.2.3 255.255.255.0 ip pim sparse-dense ! router ospf 10 network 171.69.0.0 0.0.255.255 area 0 network 10.10.10.10 0.0.0.
Configuring Multicast Source Discovery Protocol MSDP Configuration Examples interface Loopback0 ip address 192.168.1.6 255.255.255.255 no shutdown ! interface Ethernet2 description LANethernet 3 ip address 171.69.3.6 255.255.255.0 ip pim sparse-dense-mode no shutdown ! interface Ethernet5 description LANethernet 6 ip address 192.169.1.6 255.255.255.0 ip pim sparse-dense-mode ip multicast boundary 20 no shutdown ! router ospf 10 network 171.69.0.0 0.0.255.255 area 0 network 192.168.1.6 0.0.0.
Configuring PGM Host and Router Assist Note Support for the PGM Host feature has been removed. Use of this feature is not recommended. This chapter describes the PGM Host and Router Assist feature. PGM Host and Router Assist enables Cisco routers to support multicast applications that operate at the PGM transport layer and the PGM network layer, respectively. The PGM Reliable Transport Protocol itself is implemented on the hosts of the customer.
Configuring PGM Host and Router Assist PGM Overview Note PGM contains an element that assists routers and switches in handling PGM transport data as it flows through a network. Unlike the Router Assist element, the Host element does not have a current practical application. PGM is network-layer independent; PGM Host and Router Assist in the Cisco IOS software support PGM over IP. Both PGM Host and Router Assist use a unique transport session identifier (TSI) that identifies each individual PGM session.
Configuring PGM Host and Router Assist PGM Host Configuration Task List PGM Host Configuration Task List Note Support for the PGM Host feature has been removed. Use of this feature is not recommended. To configure PGM Host, perform the tasks described in the following sections. The tasks in the first section are required; the tasks in the remaining section are optional.
Configuring PGM Host and Router Assist PGM Host Configuration Task List Enabling PGM Host with a Virtual Host Interface To enable PGM Host globally on the router and to configure the router to source PGM packets through a vif, use the following command in global configuration mode: Command Purpose Router(config)# ip pgm host Enables PGM Host (both the source and receiver parts of the PGM network layer) globally on the router and configures the router to source PGM packets through a vif.
Configuring PGM Host and Router Assist PGM Host Configuration Task List 2 9CD72EF099FA 1025 source conn 48059 224.1.1.1 Specifying a traffic session number or a multicast IP address with the show ip pgm host sessions command displays information specific to that PGM transport session: Router> show ip pgm host sessions 2 Idx 2 GSI 9CD72EF099FA Source Port 1025 Type source State conn Dest Port 48059 Mcast Address 224.1.1.
Configuring PGM Host and Router Assist PGM Router Assist Configuration Task List packets received in error valid bytes received Total valid bytes received Total bytes received in error ADPUs received SPM packets received packets received in error NCF packets received packets received in error NAK packets received packets received in error packets sent Undeliverable packets General bad packets Bad checksum packets 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PGM Router Assist Configuration Task List To configure PGM Rou
Configuring PGM Host and Router Assist Monitoring and Maintaining PGM Host and Router Assist Enabling PGM Router Assist with a Virtual Host Interface To enable PGM Router Assist on a vif, use the following command in interface configuration mode: Command Purpose Router(config-if)# ip pgm router Enables the router to assist PGM on this interface.
Configuring PGM Host and Router Assist PGM Host and Router Assist Configuration Examples To enable PGM Host debugging, use the following command in privileged EXEC mode: Command Purpose Router# debug ip pgm host Displays debug messages for PGM Host. To display PGM Host information, use the following commands in user EXEC mode, as needed: Command Purpose Router> show ip pgm host defaults Displays the default values for PGM Host traffic.
Configuring PGM Host and Router Assist PGM Host and Router Assist Configuration Examples Note For clarity, extraneous information has been omitted from the examples in the following sections. PGM Host with a Virtual Interface Example Note Support for the PGM Host feature has been removed. Use of this feature is not recommended.
Configuring PGM Host and Router Assist PGM Host and Router Assist Configuration Examples no ip directed-broadcast no ip mroute-cache media-type 10BaseT interface ethernet2 ip address 10.2.0.1 255.255.255.0 ip pim dense-mode no ip directed-broadcast no ip mroute-cache media-type 10BaseT PGM Router Assist with a Virtual Interface Example The following example shows PGM Router Assist (the PGM network layer) enabled on the router and the router set up to forward PGM packets on virtual host interface 1 (vif1).
Configuring PGM Host and Router Assist PGM Host and Router Assist Configuration Examples interface ethernet2 ip address 10.2.0.1 255.255.255.
Configuring PGM Host and Router Assist PGM Host and Router Assist Configuration Examples Cisco IOS IP Configuration Guide IPC-504
Configuring Unidirectional Link Routing This chapter describes the unidirectional link routing (UDLR) feature. UDLR provides mechanisms for a router to emulate a bidirectional link to enable the routing of unicast and multicast packets over a physical unidirectional interface, such as a broadcast satellite link. However, there must be a back channel or other path between the routers that share a physical unidirectional link (UDL).
Configuring Unidirectional Link Routing UDLR Overview UDLR enables a router to emulate the behavior of a bidirectional link for IP operations over UDLs. UDLR has three complementary mechanisms for bidirectional link emulation, which are described in the following sections: • UDLR Tunnel • IGMP UDLR • IGMP Proxy You can use each mechanism independently or in conjunction with the others.
Configuring Unidirectional Link Routing UDLR Overview In a large enterprise network, it is not possible to be able to receive IP multicast traffic via satellite and forward the traffic throughout the network. This limitation exists because receiving hosts must be directly connected to the downstream router. However, you can use the IGMP Proxy mechanism to overcome this limitation. See the “IGMP Proxy” section later in this chapter for more information on this mechanism.
Configuring Unidirectional Link Routing UDLR Tunnel Configuration Task List In the scenario in Figure 82, the following sequence of events occurs: 1. User 1 joins multicast group G. 2. Router C sends a Protocol Independent Multicast (PIM) join message hop-by-hop to the rendezvous point (Router B). 3. Router B receives the PIM join message and adds a forwarding entry for group G on LAN B. 4.
Configuring Unidirectional Link Routing UDLR Tunnel Configuration Task List • On the upstream router, where the UDL can only send, you must configure the tunnel to receive. When packets are received over the tunnel, the upper-layer protocols treat the packet as though it is received over the unidirectional, send-only interface. • On the downstream router, where the UDL can only receive, you must configure the tunnel to send.
Configuring Unidirectional Link Routing IGMP UDLR Configuration Task List IGMP UDLR Configuration Task List To configure IGMP UDLR, perform the tasks described in the following sections. The tasks in the first section are required; the tasks in the remaining sections are optional.
Configuring Unidirectional Link Routing IGMP Proxy Configuration Task List See the “IGMP UDLR Example” section later in this chapter for an example of how to configure IGMP UDLR. See the “Integrated UDLR Tunnel, IGMP UDLR, and IGMP Proxy Example” section later in this chapter for an example of how to set up all three UDLR mechanisms in the same configuration. Changing the Distance for the Default RPF Interface By default, the distance for the default Reverse Path Forwarding (RPF) interface is 15.
Configuring Unidirectional Link Routing IGMP Proxy Configuration Task List Prerequisites Before configuring IGMP Proxy, ensure that the following conditions exist: • All routers on the UDL have the same subnet address. If all routers on the UDL cannot have the same subnet address; the upstream router must be configured with secondary addresses to match all the subnets that the downstream routers are attached to.
Configuring Unidirectional Link Routing UDLR Configuration Examples UDLR Configuration Examples This section provides the following UDLR examples: • UDLR Tunnel Example • IGMP UDLR Example • IGMP Proxy Example • Integrated UDLR Tunnel, IGMP UDLR, and IGMP Proxy Example UDLR Tunnel Example The following example shows how to configure a UDLR tunnel. In the example, Router A (the upstream router) is configured with Open Shortest Path First (OSPF) and PIM. Serial interface 0 has send-only capability.
Configuring Unidirectional Link Routing UDLR Configuration Examples tunnel udlr receive-only serial 0 ! ! Configure OSPF. ! router ospf network 10.0.0.0 0.255.255.255 area 0 Router B Configuration ip multicast-routing ! ! Serial1 has receive-only capability ! interface serial 1 encapsulation hdlc ip address 10.1.0.2 255.255.0.0 ip pim sparse-dense-mode ! ! Configure tunnel as send-only UDLR tunnel. ! interface tunnel 0 tunnel source 11.0.0.2 tunnel destination 11.0.0.
Configuring Unidirectional Link Routing UDLR Configuration Examples Figure 84 IGMP Unidirectional Link Routing Example Source (12.0.0.12) 12.0.0.1 Uplink router 11.0.0.1 10.0.0.1 UDL Back channel 10.0.0.2 Downlink router 13.0.0.2 Receiver (14.0.0.14) 18930 14.0.0.2 Uplink Router (uplink-rtr) Configuration ip multicast-routing ! ! Interface that source is attached to ! interface ethernet 0 description Typical IP multicast enabled interface ip address 12.0.0.1 255.0.0.
Configuring Unidirectional Link Routing UDLR Configuration Examples ! helpered for the unidirectional interface. ! interface ethernet 0 description Typical IP multicast-enabled interface ip address 14.0.0.2 255.0.0.0 ip pim sparse-dense-mode ip igmp helper-address udl serial 0 ! ! Back channel ! interface ethernet 1 description Back channel that has connectivity to downlink-rtr ip address 13.0.0.2 255.0.0.
Configuring Unidirectional Link Routing UDLR Configuration Examples Figure 85 IGMP Mroute Proxy Topology 10.1.1.1 Router A 10.3.1.1 10.2.1.1 Internet Unidirectional link 10.2.1.2 10.6.1.1 Router B 10.5.1.1 Local net Router C 46458 10.9.1.1 Router A Configuration interface ethernet 0 ip address 10.1.1.1 255.255.255.0 ip pim dense-mode ! interface ethernet 1 ip address 10.2.1.1 255.255.255.0 ip pim dense-mode ip igmp unidirectional link ! interface ethernet 2 ip address 10.3.1.1 255.255.255.
Configuring Unidirectional Link Routing UDLR Configuration Examples ! interface ethernet 1 ip address 10.5.1.1 255.255.255.0 ip pim sparse-mode ip igmp mroute-proxy loopback 0 ! interface ethernet 2 ip address 10.6.1.1 255.255.255.0 Router C Configuration ip pim rp-address 10.5.1.1 5 access-list 5 permit 239.0.0.0 0.255.255.255 ! interface ethernet 0 ip address 10.8.1.1 255.255.255.0 ip pim sparse-mode ! interface ethernet 1 ip address 10.9.1.1 255.255.255.
Configuring Unidirectional Link Routing UDLR Configuration Examples no ip directed-broadcast ip pim dense-mode ip nhrp network-id 5 ip nhrp server-only ip igmp unidirectional-link fair-queue 64 256 31 ip rsvp bandwidth 1000 100 ! router ospf 1 network 9.1.92.96 0.0.0.15 area 1 ! ip classless ip route 9.1.90.0 255.255.255.0 9.1.92.99 ! Downstream Configuration ip multicast-routing ! ! ! interface Loopback0 ip address 9.1.90.161 255.255.255.
Configuring Unidirectional Link Routing UDLR Configuration Examples no keepalive no cdp enable ! router ospf 1 network 9.1.90.0 0.0.0.255 area 1 network 9.1.92.96 0.0.0.15 area 1 ! ip classless ip route 0.0.0.0 0.0.0.0 9.1.95.1 ! set rpf to be the physical receive-only interface ip mroute 0.0.0.0 0.0.0.0 9.1.92.96 ip pim rp-address 9.1.90.
Using IP Multicast Tools This chapter describes IP multicast tools that allow you to trace a multicast path or test a multicast environment. For a complete description of the commands in this chapter, refer to the “IP Multicast Tools Commands” chapter in the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Using IP Multicast Tools MRM Configuration Task List • Can verify a multicast environment prior to an event—You need not wait for real multicast traffic to fail in order to find out that a problem exists. You can test the multicast routing environment before a planned event. • Easy diagnostics—The error information is easy for the user to understand. • Scalable—This diagnostic tool works well for many users.
Using IP Multicast Tools MRM Configuration Task List Monitoring Multiple Groups If you have more than one multicast group to monitor, you could configure an interface that is a Test Sender for one group and a Test Receiver for another group. Figure 86 illustrates an environment where the router on the left is the Test Sender for Group A and the Test Receiver for Group B.
Using IP Multicast Tools MRM Configuration Task List Command Purpose Step 2 Router(config-if)# ip mrm test-sender-receiver Configures the interface to be a Test Sender for one group and a Test Receiver for another group. Step 3 Router(config)# ip mrm accept-manager {access-list} [test-sender | test-receiver] Optionally, specifies that the Test Sender or Test Receiver can accept status report requests only from Managers specified by the access list.
Using IP Multicast Tools Monitoring IP Multicast Routing When the test begins, the Manager sends a unicast control packet to the Test Sender and Test Receiver, and then the Manager starts sending beacons. The Test Sender and Test Receiver send acknowledgments to the Manager and begin sending or receiving test packets. If an error occurs, the Test Receiver sends an error report to the Manager, which immediately displays the report. You cannot change the Manager parameters while the test is in progress.
Using IP Multicast Tools MRM Configuration Example MRM Configuration Example Figure 87 illustrates a Test Sender, a Test Receiver, and a Manager in an MRM environment. The partial configurations for the three devices follow the figure. Figure 87 Multicast Routing Monitor Example Sender Receiver Ethernet 0 10.1.1.2 IP multicast network Ethernet 0 10.1.4.
Configuring Router-Port Group Management Protocol This chapter describes the Router-Port Group Management Protocol (RGMP). RGMP is a Cisco protocol that restricts IP multicast traffic in switched networks. RGMP is a Layer 2 protocol that enables a router to communicate to a switch (or a networking device that is functioning as a Layer 2 switch) the multicast group for which the router would like to receive or forward traffic.
Configuring Router-Port Group Management Protocol RGMP Overview Figure 88 shows where these protocols operate within the IP multicast environment. Figure 88 IP Multicast Routing Protocols Internet MBONE Catalyst 5000 switch DVMRP Host CGMP Host IGMP Note 43274 PIM CGMP and RGMP cannot interoperate on the same switched network.
Configuring Router-Port Group Management Protocol RGMP Overview RGMP in a Switched Network Router B PIM SM RGMP Router A PIM SM RGMP A B B A Source for group A Switched network B Source for group B B A A A Receiver 1 for group A A Receiver 2 for group A A B Switch A RGMP IGMP snooping B Switch B RGMP IGMP snooping B Receiver 1 for group B A Router D PIM SM RGMP Router C PIM SM RGMP Traffic restricted by RGMP B 39165 Figure 89 Receiver 2 for group B In Figure 89, the sources for the
Configuring Router-Port Group Management Protocol RGMP Overview Figure 90 RGMP Messages PIM-SM RGMP RGMP IGMP Snooping PIM hello RGMP hello RGMP join X All multicast packets Multicast packets for group RGMP leave All multicast packets Multicast packets for group 42759 RGMP bye X The router sends simultaneous PIM hello (or a PIM query message if PIM Version 1 is configured) and RGMP hello messages to the switch. The PIM hello message is used to locate neighboring PIM routers.
Configuring Router-Port Group Management Protocol RGMP Configuration Task List Note An RGMP-enabled router cannot send an RGMP leave message until the router does not receive or forward traffic from any source for a specific multicast group (if multiple sources exist for a specific multicast group). The router sends the switch an RGMP bye message when RGMP is disabled on the router.
Configuring Router-Port Group Management Protocol RGMP Configuration Task List Enabling RGMP To enable RGMP, use the following commands on all routers in your network beginning in global configuration mode: Command Purpose Step 1 Router(config)# interface type number Specifies the router interface on which you want to configure RGMP and enters interface configuration mode. Step 2 Router(config-if)# ip rgmp Enables RGMP on a specified interface.
Configuring Router-Port Group Management Protocol Monitoring and Maintaining RGMP Monitoring and Maintaining RGMP To enable RGMP debugging, use the following command in privileged EXEC mode: Command Purpose Router# debug ip rgmp [group-name | group-address] Logs debug messages sent by an RGMP-enabled router. Using the command without arguments logs RGMP Join and RGMP leave messages for all multicast groups configured on the router.
Configuring Router-Port Group Management Protocol RGMP Configuration Example RGMP Configuration Example This section provides an RGMP configuration example that shows the individual configurations for the routers and switches shown in Figure 92.
Configuring Router-Port Group Management Protocol RGMP Configuration Example no shutdown Router C Configuration ip routing ip multicast-routing interface ethernet 1/0 ip address 10.4.0.1 255.0.0.0 ip pim sparse-dense-mode no shutdown interface ethernet 1/1 ip address 10.5.0.1 255.0.0.0 ip pim sparse-dense-mode ip rgmp no shutdown Router D Configuration ip routing ip multicast-routing interface ethernet 1/0 ip address 10.6.0.1 255.0.0.
Configuring Router-Port Group Management Protocol RGMP Configuration Example Cisco IOS IP Configuration Guide IPC-536
Configuring DVMRP Interoperability This chapter describes the Distance Vector Multicast Routing Protocol (DVMRP) Interoperability feature. For a complete description of the DVMRP commands in this chapter, refer to the “IP Multicast Routing Commands” chapter of the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
Configuring DVMRP Interoperability Basic DVMRP Interoperability Configuration Task List Configuring DVMRP Interoperability Cisco multicast routers using PIM can interoperate with non-Cisco multicast routers that use the DVMRP. PIM routers dynamically discover DVMRP multicast routers on attached networks. Once a DVMRP neighbor has been discovered, the router periodically sends DVMRP report messages advertising the unicast sources reachable in the PIM domain.
Configuring DVMRP Interoperability Basic DVMRP Interoperability Configuration Task List 171.69.214.203 -> 0.0.0.0 [1/0/pim/querier/down/leaf] 171.69.214.18 -> 171.69.214.20 (mm1-45e.cisco.com) [1/0/pim] 171.69.214.18 -> 171.69.214.19 (mm1-45c.cisco.com) [1/0/pim] 171.69.214.18 -> 171.69.214.17 (mm1-45a.cisco.com) [1/0/pim] See the “DVMRP Interoperability Example” section later in this chapter for an example of how to configure a PIM router to interoperate with a DVMRP router.
Configuring DVMRP Interoperability Advanced DVMRP Interoperability Configuration Task List See the “DVMRP Tunnel Example” section later in this chapter for an example of how to configure a DVMRP tunnel. Advertising Network 0.0.0.0 to DVMRP Neighbors The mrouted protocol is a public domain implementation of DVMRP. If your router is a neighbor to an mrouted Version 3.6 device, you can configure the Cisco IOS software to advertise network 0.0.0.0 to the DVMRP neighbor.
Configuring DVMRP Interoperability Advanced DVMRP Interoperability Configuration Task List When DVMRP unicast routing is enabled, the router caches routes learned in DVMRP report messages in a DVMRP routing table. PIM prefers DVMRP routes to unicast routes by default, but that preference can be configured. DVMRP unicast routing can run on all interfaces, including generic routing encapsulation (GRE) tunnels. On DVMRP tunnels, it runs by virtue of DVMRP multicast routing.
Configuring DVMRP Interoperability Advanced DVMRP Interoperability Configuration Task List Command Purpose Router(config-if)# ip dvmrp summary-address summary-address mask [metric value] Specifies a DVMRP summary address. Note At least one, more-specific route must be present in the unicast routing table before a configured summary address will be advertised. Disabling DVMRP Automatic summarization By default, the Cisco IOS software performs some level of DVMRP summarization automatically.
Configuring DVMRP Interoperability Advanced DVMRP Interoperability Configuration Task List Rejecting a DVMRP Nonpruning Neighbor By default, Cisco routers accept all DVMRP neighbors as peers, regardless of their DVMRP capability or lack of. However, some non-Cisco machines run old versions of DVMRP that cannot prune, so they will continuously receive forwarded packets unnecessarily, wasting bandwidth. Figure 93 shows this scenario.
Configuring DVMRP Interoperability Advanced DVMRP Interoperability Configuration Task List Figure 94 Router Rejects Nonpruning DVMRP Neighbor Source or RP RP Router A Multicast traffic gets to receiver, not to leaf DVMRP machine Router B Receiver Router C Leaf nonpruning DVMRP machine 43277 ip dvmrp reject-non-pruners Note that the ip dvmrp reject-non-pruners command prevents peering with neighbors only.
Configuring DVMRP Interoperability Monitoring and Maintaining DVMRP Monitoring and Maintaining DVMRP To clear routes from the DVMRP routing table, use the following command in EXEC mode: Command Purpose Router# clear ip dvmrp route { * | route} Deletes routes from the DVMRP routing table. To display entries in the DVMRP routing table, use the following command in EXEC mode: Command Purpose Router# show ip dvmrp route [name | ip-address | type number] Displays the entries in the DVMRP routing table.
Configuring DVMRP Interoperability DVMRP Configuration Examples ip unnumbered ethernet 0 ip pim dense-mode tunnel source ethernet 0 tunnel destination 192.70.92.133 tunnel mode dvmrp ! interface ethernet 0 description Universitat DMZ-ethernet ip address 192.76.243.2 255.255.255.
Index
INDEX Symbols address family configuration, NLRI to address family configuration, converting IPC-350 address pools xli ? command names, creating xl IPC-69 obtaining IP addresses IPC-65 address ranges, summarizing A accept-lifetime command DRP route authentication access-class command OSPF IPC-230 adjacency levels, IS-IS, specifying IPC-266 IPC-88, IPC-99 access groups, IP IPC-99 BGP, setting definition access-list compiled command IPC-372 agent command IPC-144 IPC-145 aggrega
Index timeout routing for destinations outside autonomous system IPC-229 IPC-14 tables auto-summary (BGP) command IP contents, displaying defining static IPC-13 arp arpa command auto-summary (Enhanced IGRP) command IPC-14 auto-summary (RIP) command IPC-14 arp snap command IPC-206 B IPC-14 arp timeout command IPC-14 backup, stateless ATM IPC-139 bandwidth percentage for EIGRP SVC, point-to-multipoint VC status, displaying IPC-434, IPC-436 beacon command IPC-447 IPC-436 defaults dyn
Index configuring route maps IPC-293 to IPC-327 connections route reflector immediately, resetting EBGP status, displaying filter IPC-317 to IPC-320 route selection rules IPC-311 IPC-293 routing domain confederation IPC-332 default local preference value, changing enabling IPC-367 IPC-326 supernets IPC-311 synchronization with IGPs IPC-297 IPC-316 IPC-302 TCP MD5 authentication IPC-321 IP routing table, updating for a neighbor IPC-325 mesh reduction IPC-323 for a peer group IP
Index types benefits IPC-31 IPC-66 boot file, specifying configuration task list C IPC-68 database agent configuration (example) carriage return () enabling xli cautions, IP access lists monitoring and maintaining CDP (Cisco Discovery Protocol) dialer mappings, using with overview IPC-198 reconvergence of IP routes timeout value IPC-197 prerequisites cdp timer command IPC-73 IPC-67 clear arp-cache command IPC-196 clear host command IPC-196 Forwarding Agent, enabling IPC-119
Index clear ip pim auto-rp command clear ip route command IPC-446 D IPC-47, IPC-378 clear ip route dhcp command DDR (dial-on-demand routing), CDP packets IPC-76 clear ip rtp header-compression command clear ip sap command debug ip icmp command IPC-119 client hardware address, specifying client-identifier command IPC-73 IPC-72 IPC-72 command modes, understanding xxxix to xl IPC-76 IPC-120 context-sensitive help for abbreviating xl IPC-170 debug ip mobile host command IPC-170 debug ip
Index configuration messages dhcpack Server Agent IPC-66 dhcpdecline dhcpoffer authenticate queries and responses IPC-66 dhcpdiscover description IPC-66 enabling IPC-66 options, autoconfiguring server boot file, specifying distance bgp command distance command statistics, clearing IPC-198 IPC-86 IPC-119 DVMRP (Distance Vector Multicast Routing Protocol) IPC-325 routes, redistribute into multiprotocol BGP IPC-372 DistributedDirector dynamic inbound soft reset, BGP IPC-85 distribute-l
Index split horizon, enabling See also access lists, IP IPC-267 See also access lists, IP stub routing benefits flexible netmask display IPC-271 configuration tasks configuring overview verifying Flow Delivery Agent IPC-272 See ContentFlow architecture, Flow Delivery Agent IPC-268 Foreign Agent services, enabling (Mobile IP) IPC-268 restrictions See MNLB Forwarding Agent IPC-272 forwarding-agent command IPC-266, IPC-267 eigrp log-neighbor-changes command eigrp stub command IPC-168 Forw
Index helper addresses I IP (example) ICMP (Internet Control Message Protocol) IPC-60 configuring customizing services (example) IPC-32 hit table count, clearing prefix list entries ICMP mask reply messages, enabling IPC-308 ICMP redirect messages holddown definition IPC-121 IPC-83 IPC-83 ICMP unreachable messages, enabling IPC-214 IPC-82 disabling, IGRP IPC-218 idle command hold time, EIGRP IPC-267 IGMP (Internet Group Management Protocol) home agent redundancy, Mobile IP host comm
Index IP traffic, routing helper (example) IPC-30 interface configuration mode, summary of IPC-60 interfaces, assigning to xl interfaces list of reserved (table) circuit type, IS-IS, setting multiple assigning multiple primary primary interface tunnel command IPC-9, IPC-50 addressing monitoring tasks IPC-509 Interior Gateway Routing Protocol See IGRP IPC-9 IPC-8 secondary IPC-9 address resolution IP IPC-12 advertising, definition access lists authentication keys extended, applyi
Index named access lists IPC-91 ip accounting-transits command IPC-109 IPC-9 name server, specifying IPC-17 ip address (secondary) command performance parameters IPC-110 ip address command PIM primary IP address, setting See IP multicast routing, PIM policy routing fast switched precedence (table) ip address dhcp command IP addresses, static IPC-373, IPC-376 IPC-8 IPC-73 IPC-67 ip authentication key-chain eigrp command IPC-377 ip authentication mode eigrp command IPC-374 ip bandwidth-
Index ip dvmrp metric mbgp command IPC-355 ip mobile home-agent standby command ip dvmrp metric-offset command IPC-542 ip mobile host command ip dvmrp reject-non-pruners command IPC-544 ip dvmrp routehog-notification command ip dvmrp route-limit command IPC-541 ip dvmrp summary-address command ip dvmrp unicast-routing command IPC-541 ip forward-protocol spanning-tree command ip forward-protocol turbo-flood command ip helper-address command IPC-34 IPC-34 ip mrm manager command IPC-524 ip mro
Index CGMP statically connected router member clearing IPC-446 version, changing enabling IPC-440 Version 1 IPC-410 Version 2 IPC-411 Version 3 IPC-411 proxy IPC-440 debug messages, logging designated router diagnostic tool IPC-415 clearing IPC-521 automatic summarization IPC-542 IPC-543 reject nonpruning neighbors route hog notification IPC-544 IPC-541 routes IPC-402 IPC-457 native route threshold IPC-541 summary address unicast routing MBONE monitoring tasks IPC-526 IPC
Index mroute description IPC-471 enabling IPC-475 packet forwarding IPC-429 mrouted advertising routes description IPC-540 IPC-538 tunnel interface destination address IPC-539 MSDP benefits prerequisites (example) IPC-449 configuring IPC-405 description IPC-405 IPC-480 IPC-479 description controlling host access to displaying IPC-409 peering IPC-446 maximum number of VCs neighbors, displaying PGM See also IP multicast routing, PGM Host See also IP multicast routing, PGM Router Assist p
Index description stub multicast routing IPC-528 monitoring and maintaining prerequisites verifying (example) IPC-533 description IPC-531 testing IPC-532 RP (rendezvous point) IPC-440 IPC-521 Token Ring, over address, configuring (example) IPC-406 Auto-RP IPC-449 description groups covered mapping agent displaying IPC-407 Token Ring MAC address mapping TTL threshold back channel IPC-408 description IPC-417 RP-mapping agent to a group, assigning RTP header compression IPC-430 IPC
Index ip nhrp holdtime command ip nhrp interest command ip nhrp map command IPC-21, IPC-49 IPC-25 ip nhrp network-id command ip nhrp trigger-svc command IPC-24 IPC-226 IPC-225 ip ospf demand-circuit command IPC-234 ip ospf flood-reduction command IPC-238 ip ospf name-lookup command IPC-226 IPC-227, IPC-228 ip ospf priority command IPC-225 ip ospf transmit-delay command IPC-225 IPC-225 IPC-83 IPC-532 IPC-203 ip rip authentication mode command ip rip send version command IPC-203 IPC-202
Index ip tcp chunk-size command retransmission level, setting IPC-114 ip tcp compression-connections command ip tcp finwait-time command route redistribution IPC-112 system type IPC-114 IPC-281 IPC-367 IPC-284 ip tcp header-compression command IPC-111 isis circuit-type command ip tcp path-mtu-discovery command IPC-113 isis csnp-interval command IPC-280 isis hello-interval command IPC-280 ip tcp queuemax command IPC-115 IPC-282 ip tcp selective-ack command IPC-113 isis hello-multipl
Index lock-and-key access, dynamic access list log-adj-changes command IPC-88 IPC-235 log neighbor adjacencies,EIGRP IPC-260 loopbacks, use with OSPF IPC-232 lsp-gen-interval command IPC-288 lsp-refresh-interval command in choosing a subautonomous system path in a confederation IPC-328 missing IPC-327 with value of infinity IPC-294 messages Internet broadcast, establishing IPC-287 IP, destination unreachable metric holddown command M IPC-84 IPC-218 metric maximum-hops command MAC addres
Index overview security IPC-115 port number, specifying related documentation keys IPC-118 wildcard blocks, displaying virtual networks IPC-118 IPC-115 agent advertisements See IP multicast routing, MRM IPC-161 mrm command IPC-161 agent solicitations authentication See IP multicast routing, mrouted MSDP (Multicast Source Discovery Protocol) IPC-163, IPC-164 See IP multicast routing, MSDP IPC-162 configuration tasks mstat command IPC-167 denial-of-service attack IPC-162 foreign agent
Index neighbor advertisement-interval command N neighbor database-filter command named IP access lists IPC-91 configuring neighbor description command IPC-35 IPC-46 dynamic entries, clearing dynamic translations neighbor filter-list command IPC-38, IPC-39 local address IPC-36 neighbor password command IPC-36 source translation IPC-37 IPC-61 IP Phone to Cisco CallManager, support of IPC-46 outside IPC-309 IPC-320 neighbor remote-as command IPC-297, IPC-350 neighbor route-map command
Index enabling OSPF enabling RIP traffic monitoring IPC-225 tunnel (example) IPC-200 network diameter, enforcing (IGRP) network masks, format IPC-218 OSPF IPC-58 IPC-27 Virtual Private Network IPC-47 network numbers BGP tunnel network IPC-49 IPC-19 NLRI (network layer reachability information) keywords IPC-293 IPC-230 new information in this release xxxiii IPC-350 NLRI to address family configuration, converting IPC-350 nonbroadcast networks, configuring OSPF Next Hop Resolution Protoc
Index broadcast or nonbroadcast networks, configuring for IPC-226 checksum pacing defining an NSSA on-demand circuit IPC-236 Cisco implementation packet pacing IPC-223 IPC-249, IPC-388 refresh pacing IPC-231 IPC-241 IPC-224 IPC-232 default routes, generating IPC-229 enabling route redistribution (example) IPC-245, IPC-384 IPC-232 IPC-225 IPC-230 simplex Ethernet interfaces, configuring IPC-232 stub area, defining IPC-230 transmission time for link-state updates, setting IPC-225 ignore
Index permit command IPC-91 Q PGM (Pragmatic General Multicast) question mark (?) command See IP multicast routing, PGM xl PIM (Protocol Independent Multicast) See IP multicast routing, PIM ping command R IPC-446 IP privileged user RARP (Reverse Address Resolution Protocol) definition IPC-13 IPC-48 real command IPC-48 ping reply, specifying how long to wait ping timeout, specifying duration IPC-73 release notes, identify using IPC-524 redistribute command xlv IPC-355 redistribution IGR
Index subnetting RFC 1348 IPC-9 DNS NSAP RRs RFC 792 Internet Control Message Protocol (ICMP) IPC-81 RFC 826 ARP IPC-17 RFC 1403, BGP/OSPF interaction IPC-334 RFC 1469 IPC-13 RFC 862, Echo TCP and UDP service IPC-1 RFC 863, Discard TCP and UDP service IPC-1 RFC 1531 Dynamic Host Configuration Protocol (DHCP) RFC 903 RARP IP Multicast over Token-Ring Local Area Networks IPC-416 RFC 1567, NSSA (not so stubby areas) IPC-13 RFC 1583, OSPF Version 2 RFC 919 Broadcasting Internet Datagrams
Index automatic route summarization, disabling enabling specifying IPC-199 redistribution (example) route summarization running with IGRP IGRP types IPC-203 route summarization version, specifying IPC-207 IPC-202 ROM monitor mode, summary of IPC-203 routing, information, filtering task list IPC-316 BGP IPC-265 updates IPC-203 IPC-299 routing tables route-map command BGP for policy routing IPC-373 attributes for redistribution IPC-367 updates route maps IPC-303 IPC-300 updates
Index description enabling express service dhcp command IPC-430 services manager IPC-432 See MNLB services manager IPC-433 sessions Frame Relay encapsulation (example) using BGP IPC-453 default version IPC-432 Frame Relay statistics, displaying passive resetting IPC-446 PPP encapsulation (example) IPC-368 set community command IPC-368 set dampening command IPC-368 set interface command IPC-431 S set ip default next-hop command IPC-374 set ip next-hop (BGP) command IPC-309 set i
Index show ip aliases command show ip arp command IPC-48 IPC-48 show ip bgp cidr-only command show ip bgp command show ip mobile globals command IPC-170 IPC-170 show ip mobile host group command show ip bgp community command IPC-332 show ip bgp community-list command IPC-332 show ip bgp dampened-paths command show ip bgp filter-list command IPC-331 IPC-332 show ip bgp flap-statistics command IPC-330 show ip bgp inconsistent-as command show ip bgp neighbors command IPC-332 show ip bgp pee
Index show ip pim rp command IPC-408, IPC-447, IPC-476 show ip pim rp-hash command show ip pim vc command IPC-447 show ip policy command IPC-378 show ip protocols command See IP multicast routing, SSM IPC-170 IPC-48, IPC-378 show ip route supernets-only command show ip rpf command standby ip command IPC-76 show ip route summary command IPC-378 IPC-447 show ip tcp header-compression command show isis routes command show key chain command IPC-379 show route-map command IPC-379 simplex ci
Index IP, creating network from separated, (example) use of subnet zero, enabling IPC-50 window size IPC-114 See also TCP/IP header compression IPC-9 TCP/IP variable length subnet masks (example) IPC-244, IPC-379 header compression, express definition IPC-364 overview summary-address (OSPF) command summary-address command IPC-231 IPC-302 EIGRP IPC-325 IPC-267 EIGRP, adjusting IGRP, adjusting IPC-302 RIP, adjusting IPC-340 synchronization command IPC-266 IPC-217 IPC-201 timers basi
Index tunnel udlr receive-only command tunnel udlr send-only command IPC-509 IPC-120 IPC-509 Turbo ACL (Access Control List) turbo flooding wildcard blocks, status, displaying IPC-96 IPC-34 U UDLR (unidirectional link routing) See IP multicast routing, UDLR UDP (User Datagram Protocol) broadcast addresses, establishing IPC-33 datagrams flooding IPC-34 speeding up flooding turbo flooding IPC-34 using with RIP IPC-199 udp-port command IPC-34 IPC-524 update broadcast (IGRP) IPC-214 user E
Index Cisco IOS IP Configuration Guide IN-578
