C H A P T E R 4 Configuring Interfaces This chapter describes basic interface configurations for your Layer 3 switch router. Also included are sections about configuring virtual LANs (VLANs), packet-over-SONET interfaces, ATM uplink interfaces, and port snooping. Unless otherwise noted, the information in this chapter applies to the Catalyst 8540 CSR, Catalyst 8510 CSR, and Catalyst 8540 MSR with Layer 3 functionality.
Chapter 4 Configuring Interfaces Overview of Interface Configuration Overview of Interface Configuration A router’s main function is to relay packets from one data link to another. To do that, the characteristics of the interfaces through which the packets are received and sent must be defined. Interface characteristics include, but are not limited to, IP address, address of the port, data encapsulation method, and media type. Many features are enabled on a per-interface basis.
Chapter 4 Configuring Interfaces General Instructions for Configuring Interfaces Figure 4-1 Interface Port Identifier Format The slot in which the interface module or port adapter is installed. Slots are numbered starting at 0. The subslot in which the interface module or port adapter is installed. For a full-width interface module, this number is always 0. The port or interface number on the interface module or port adapter. Numbering always starts at 0 and goes from left to right.
Chapter 4 Configuring Interfaces About Layer 3 Switching Interfaces Step 3 Follow each interface command with the interface configuration commands required for your particular interface. The commands you enter define the protocols and applications that will run on the interface. The commands are collected and applied to the interface command until you enter another interface command, a command that is not an interface configuration command, or you enter end to return to privileged EXEC mode.
Chapter 4 Configuring Interfaces About Layer 3 Switching Interfaces Initially Configuring Gigabit Ethernet Interfaces To configure an IP address and autonegotiation on a Gigabit Ethernet interface, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface gigabitethernet slot/subslot/interface Enters Ethernet interface configuration mode to configure the Gigabit Ethernet interface.
Chapter 4 Configuring Interfaces About Layer 3 Switching Interfaces Initially Configuring Fast Ethernet Interfaces Use the following procedure to assign an IP address to the Fast Ethernet 10BaseT or 100BaseT interface of your switch router so that it can be recognized as a device on the Ethernet LAN. The Fast Ethernet interface supports 10-Mbps and 100-Mbps speeds with Cisco 10BaseT and 100BaseT routers, hubs, switches, and switch routers.
Chapter 4 Configuring Interfaces About Layer 3 Switching Interfaces Examples The following example shows sample output from the show interface gigabitethernet command: Router# show interface gigabitethernet 0/0/0 GigabitEthernet0/0/0 is administratively down, line protocol is down Hardware is K1 Gigabit Port, address is 00d0.ba1d.3207 (bia 00d0.ba1d.3207) Internet address is 10.1.2.
Chapter 4 Configuring Interfaces About Virtual LANs About Virtual LANs Virtual LANs enable network managers to group users logically rather than by physical location. A virtual LAN (VLAN) is an emulation of a standard LAN that allows data transfer and communication to occur without the traditional restraints placed on the network. It can also be considered a broadcast domain set up within a switch.
Chapter 4 Configuring Interfaces Configuring ISL VLAN Encapsulation Figure 4-2 Example of an ISL VLAN Bridging Configuration Bridge-group 1 1/0/1.1 1/0/0 VLAN 50 encap isl 50 encap isl 100 Campus switch router Campus switch router VLAN 100 1/0/1.2 17489 3/0/1 Bridge-group 2 To configure the Layer 3 VLANs shown in Figure 4-2, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface fastethernet slot/subslot/interface.
Chapter 4 Configuring Interfaces Configuring 802.1Q VLAN Encapsulation Example The following example shows how to configure the interfaces for VLAN bridging with ISL encapsulation shown in Figure 4-2: Router(config)# interface fastethernet 1/0/1.
Chapter 4 Configuring Interfaces Configuring 802.1Q VLAN Encapsulation Figure 4-3 Example of Bridging Between Native and Non-Native 802.1Q VLANs Bridge-group 1 1/0/1.1 1/0/0 Native VLAN 1 encap dot1q 1 native encap dot1q 100 Campus switch router Campus switch router Non-native VLAN 100 1/0/1.
Chapter 4 Configuring Interfaces Monitoring VLAN Operation Example The following example shows how to configure the bridging between native and non-native 802.1Q VLANs shown in Figure 4-3: Router(config)# interface fastethernet 1/0/1.
Chapter 4 Configuring Interfaces About the POS OC-12c Uplink Interface Because SONET/SDH (Synchronous Digital Hierarchy) is by definition a point-to-point circuit, PPP is well suited for use over SONET links. The octet stream is mapped into the SONET/SDH synchronous payload envelope (SPE) in accordance with RFC 2615, “PPP over SONET/SDH,” and RFC 2615, “PPP in HDLC-like Framing.” Octet boundaries are aligned with the SPE octet boundaries, and the PPP frames are located by row within the SPE payload.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Figure 4-5 shows an example of a service provider application of the POS OC-12c uplink interface module. Here traffic is aggregated from Catalyst 8500 CSRs over POS OC-12c interfaces to Cisco 12000 GSRs. POS OC-48 interfaces on the Cisco 12000 gigabit switch routers then provide the uplinks to the Internet backbone.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Default Configuration Table 4-1 shows the default configuration of an enabled POS OC-12c uplink interface. To change any of these values, see the instructions in the following sections, “Initially Configuring the POS Interface” and “Customizing the Configuration.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) To initially configure the POS OC-12c uplink interface, perform the following steps, beginning in global configuration mode: Command Purpose Step 1 Router(config)# ip routing Enables IP routing. Step 2 Router(config)# interface pos slot/subslot/interface Enters interface configuration mode and specifies the POS interface to configure.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Additional Configurations To configure additional properties to match those of the interface at the far end, perform the following steps, beginning in global configuration mode: Command Purpose Step 1 Router(config-if)# no keepalive Turns off keepalive messages. Keepalive messages, though not required, are recommended. Step 2 Router(config-if)# no cdp enable Turns off CDP, which is not required.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Configuring Framing The default framing mode for the POS OC-12c uplink interface is SONET STS-12c. You can also configure the interface for SDH STM-4, which is more widely used in Europe.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) The value of the c2 byte is determined as follows: • If the value of the c2 byte has not been explicitly configured with the pos flag command, the SONET framer sends the following values: – For Cisco HDLC encapsulation with or without SPE scrambling: 0xCF – For PPP encapsulation with scrambling: 0x16 (RFC 2615) – For PPP encapsulation without scrambling: 0xCF (RFC 2615) • If the value of the c2 byte has been ex
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Configuring SONET Alarms The OC-12c POS uplink interface supports SONET alarm monitoring. To configure alarm monitoring, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface pos slot/subslot/interface Enters interface configuration mode and specifies the POS interface to configure.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Configuring SONET Delay Triggers A trigger is an alarm, which when asserted causes the line protocol to go down.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) To configure a delay in triggering the line protocol of the interface from going down, perform the following steps beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface pos slot/subslot/interface Enters interface configuration mode and specifies the POS interface to configure.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Examples The following example shows output for the show interfaces pos command: Router# show interfaces pos 1/0/0 POS1/0/0 is up, line protocol is down Hardware is Packet Over SONET Internet address is 10.1.2.
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) The following example shows output for the show controllers pos command: Router# show controllers pos 2/0/0 Interface POS2/0/0 Hardware is Packet Over SONET, One-port OC12, Single Mode Intermediate Reach POS2/0/0 SECTION LOF = 1 LINE AIS = 0 PATH AIS = 0 LOP = 1 PLM-P = 1 LOS = 0 BIP(B1) = 96 RDI = 1 FEBE = 265 BIP(B2) = 1170 RDI = 1 FEBE = 78 BIP(B3) = 51 UNEQ-P = 0 Active Alarms: None Active Defects:N
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) The following example shows output for the show controllers pos command with the detail option: Router# show controller pos 2/0/0 detail Interface POS2/0/0 Hardware is Packet Over SONET, One-port OC12, Single Mode Intermediate Reach POS2/0/0 SECTION LOF = 1 LINE AIS = 0 PATH AIS = 0 LOP = 1 PLM-P = 1 LOS = 0 BIP(B1) = 96 RDI = 1 FEBE = 265 BIP(B2) = 1170 RDI = 1 FEBE = 78 BIP(B3) = 51 UNEQ-P = 0 Active A
Chapter 4 Configuring Interfaces Configuring the POS OC-12c Uplink Interface (Catalyst 8540) Interrupt Mask Register = 0x0001 Parity Error Register = 0x0000 Scratch Register = 0x80000000 Debug Register = 0x0000 CRC32 enabled, PPP enc, Diag control reg 1:0x0 GPIO port:loop timed GPIO port:no loop ----- Skystone Performance Monitor Counters ----rpp_pm1 rpp_pm2 rpp_pm3 rpp_pm4 rpp_pm5 rpp_pm6 rpp_pm7 (packet) (bytes ) (crc ) (runts ) (giants) (ignore) (abort ) = = = = = = = 1154 36225 105 67 0 142 0 tpp
Chapter 4 Configuring Interfaces About ATM Uplinks (Catalyst 8540) SR1 72036 SR2 18806 SR3 0 SR4 0 SR5 0 MT1 MT6 ST1 MRXS 15143 0 0 262160 MT2 MT7 ST2 MTXS 0 0 0 16 MT3 MT8 0 0 MT4 MT9 0 0 MT5 6 SRXS 3 STXS 0 About ATM Uplinks (Catalyst 8540) ATM uses cell-switching and multiplexing technology that combines the benefits of circuit switching (constant transmission delay and guaranteed capacity) with those of packet switching (flexibility and efficiency for intermittent traffic).
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Note The ATM uplink interface module does not work in a Catalyst 8540 MSR when the ATM router module is present.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Table 4-4 ATM Uplink Interface Default Configuration Values (continued) Parameter Configuration Command Default Value Transmit clock source [no] atm clock internal no internal (line) Cisco Discovery Protocol (CDP) [no] cdp enable CDP enabled ATM VCs per VP 1024 atm vc-per-vp In addition, the ATM uplink interface uses the non-configurable values shown in Table 4-5.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Example The following configuration is an example of the tasks in the preceding table: Router(config)# interface atm 2/0/0 Router(config-if)# ip address 10.1.2.4 255.0.0.0 Router(config-if)# atm clock internal Router(config-if)# no shutdown Configuring the Clock Source The ATM uplink interfaces support internal and line clock source. The default mode for the clock is no internal, which is the same as the line clock.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Note The ATM uplink supports IP unicast and IP multicast fragmentation. For IP unicast fragmentation, the packet must ingress on a ATM interface and egress on any interface. For IP multicast fragmentation, IP multicast data packets greater than 1500 bytes are fragmented to 1500 bytes on the ingress ATM interface before being switched to other members in the multicast group.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) To configure the SONET overhead, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface atm slot/subslot/interface Enters interface configuration mode and specifies the ATM interface to configure. Router(config-if)# Step 2 Router(config-if)# sonet Configures the SONET overhead bytes.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Configuring SONET Alarms The ATM OC-12c and the ATM OC-3c uplink interfaces support SONET alarm monitoring. To configure alarm monitoring, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface atm slot/subslot/interface Enters interface configuration mode and specifies the ATM interface to configure.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Configuring CDP The ATM uplink interface is configured by default with Cisco Discovery Protocol (CDP) disabled. To enable CDP, use the cdp enable command in interface configuration mode. Configuring the Maximum VCs per VP The ATM uplink interface is configured by default to allow a maximum of 1024 VCs per VP.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) To create a PVC, perform the following steps, beginning in global configuration mode: Step 1 Command Purpose Router(config)# interface atm slot/subslot/interface Enters interface configuration mode and specifies the ATM interface to configure.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) SVC Example In the following example, two switch routers with Layer 3 enabled ATM interfaces are connected by means of SVCs. For SVCs, the map-list associates each IP addresses with an ATM NSAP-format address, rather than with a specific VC.
Chapter 4 Configuring Interfaces Configuring the ATM Uplink Interface (Catalyst 8540) Example The following example shows sample output for the show interfaces atm command. Router# show interfaces atm 0/0/0 ATM0/0/0 is down, line protocol is down Hardware is epif_port_garfield, address is 0090.2157.c407 (bia 0090.2157.
Chapter 4 Configuring Interfaces About Port Snooping Interface Configuration Mode: ATM clock line; STS-3c k1/k2 = 0/0 c2 = 0x13 Active Defects:None Alarm reporting enabled for:SF SLOS SLOF B1-TCA B2-TCA PLOP B3-TCA Active ATM Payload Defect:None OC3 counters: b1 - # section BIP-8 errors b2 - # line BIP-8 errors b3 - # path BIP-8 errors ocd - # out-of-cell delineation errors - not implemented g1 - # path FEBE errors z2 - # line FEBE errors chcs - # correctable HEC errors uhcs - # uncorrectable HEC errors
Chapter 4 Configuring Interfaces Configuring Snooping Restrictions on Port Snooping The following restrictions apply to port snooping: • The combined physical bandwidth of the source ports must not exceed the physical bandwidth of the destination port. • The snooping source port and destination port cannot be the same port. • Port snooping is not available on the eight-port Gigabit Ethernet interfaces.
Chapter 4 Configuring Interfaces Configuring Snooping Command Purpose Router(config)# interface destination-port Router(config-if)# Defines the interface configuration for the destination (test) port. Step 2 Router(config-if)# shutdown Shuts down the destination port. Step 3 Router(config-if)# snoop interface source-port direction {receive | transmit | both} Defines a snoop source port and its snoop direction. You must issue separate snoop interface commands for each source port.
Chapter 4 Configuring Interfaces Monitoring Snooping Monitoring Snooping To monitor the current snooping mode configuration and status, use the following commands: Command Purpose show snoop interface destination-port Displays whether the indicated destination port is in snooping mode. If so, it indicates the source (monitored) port and the snooping direction. show snoop Displays all the snoop sessions configured on the system.
Chapter 4 Configuring Interfaces Monitoring Snooping Layer 3 Switching Software Feature and Configuration Guide 4-42 78-6235-04, Cisco IOS Release 12.