HP FlexFabric 11900 Switch Series Layer 3 - IP Routing Configuration Guide Part number: 5998-4061 Software version: Release 2105 and later Document version: 6W100-20130515
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Contents IP routing basics ··························································································································································· 1 Routing table ······································································································································································ 1 Dynamic routing protocols ······················································································································
Configuring an additional routing metric ··········································································································· 24 Configuring RIPv2 route summarization·············································································································· 25 Disabling host route reception ····························································································································· 26 Advertising a default route ·····················
Configuring OSPF areas ··············································································································································· 60 Configuring a stub area ······································································································································· 60 Configuring an NSSA area·································································································································· 60 Configuring a virtual
Configuring bidirectional control detection ········································································································ 80 Configuring single-hop echo detection ··············································································································· 81 Configuring OSPF FRR ··················································································································································· 81 Configuration prerequisites ·······
Advertising a default route ································································································································· 126 Configuring IS-IS route redistribution ················································································································ 126 Configuring IS-IS route filtering ·························································································································· 127 Configuring IS-IS route leaking ·
BGP path attributes ············································································································································· 164 BGP route selection ············································································································································· 168 BGP route advertisement rules ··························································································································· 169 BGP load balancing ···
Configuring a BGP route reflector ····················································································································· 226 Configuring a BGP confederation ····················································································································· 227 Configuring BGP GR ··················································································································································· 228 Enabling trap ·················
Configuring BFD for IPv6 static routes ······················································································································· 283 Bidirectional control mode ································································································································· 284 Single-hop echo mode ········································································································································ 285 Displaying and maintaining
Configuring a stub area ····································································································································· 311 Configuring an OSPFv3 virtual link ··················································································································· 312 Configuring OSPFv3 network types ··························································································································· 312 Configuration prerequisites ······
IPv6 IS-IS basic configuration example ············································································································· 341 BFD for IPv6 IS-IS configuration example ········································································································· 345 Configuring IPv6 PBR ·············································································································································· 349 Introduction to IPv6 PBR ··············
Websites······························································································································································· 368 Conventions ·································································································································································· 369 Index ··························································································································································
IP routing basics The term "interface" in the routing features collectively refers to Layer 3 interfaces, including VLAN interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a Layer 3 interface by using the port link-mode route command (see Layer 2—LAN Switching Configuration Guide). IP routing directs IP packet forwarding on routers based on a routing table. This chapter focuses on unicast routing protocols.
2.2.2.0/24 Static 60 0 12.2.2.2 Vlan2 80.1.1.0/24 OSPF 2 80.1.1.1 Vlan3 10 ... A route entry includes the following key items: • Destination—IP address of the destination host or network. • Mask—Mask length of the IP address. • Pre—Preference of the route. Among routes to the same destination, the route with the highest preference is optimal. • Cost—If multiple routes to a destination have the same preference, the one with the smallest cost is the optimal route. • NextHop—Next hop.
Route preference Routing protocols, including static and direct routing, each by default have a preference. If they find multiple routes to the same destination, the router selects the route with the highest preference as the optimal route. The preference of a direct route is always 0 and cannot be changed. You can configure a preference for each static route and each dynamic routing protocol. The following table lists the route types and default preferences.
Configuring route recursion To use a route with an indirect next hop, a device must perform route recursion to find the outgoing interface to reach the next hop. Route recursion ensures the convergence speed of routes with indirect next hops. To keep the routing table size, HP recommends not configuring route recursion when ECMP load sharing is performed or too many route entries are available in the routing table. The configuration takes effect at next reboot.
Task Command Display routing table information. display ip routing-table [ vpn-instance vpn-instance-name ] [ verbose ] Display information about routes permitted by an IPv4 basic ACL. display ip routing-table [ vpn-instance vpn-instance-name ] acl acl-number [ verbose ] Display information about routes to a specific destination address.
Configuring static routing Static routes are manually configured. If a network's topology is simple, you only need to configure static routes for the network to work correctly. Static routes cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually. Configuring a static route Before you configure a static route, complete the following tasks: • Configure the physical parameters for related interfaces.
Step 4. (Optional.) Delete all static routes, including the default route. Command Remarks delete [ vpn-instance vpn-instance-name ] static-routes all To delete one static route, use the undo ip route-static command. Configuring BFD for static routes IMPORTANT: Enabling BFD for a flapping route could worsen the situation. BFD provides a general-purpose, standard, medium-, and protocol-independent fast failure detection mechanism.
Step Command Remarks • Method 1: 2. Configure BFD control mode for a static route. ip route-static dest-address { mask | mask-length } { next-hop-address bfd control-packet bfd-source ip-address | vpn-instance d-vpn-instance-name next-hop-address bfd control-packet bfd-source ip-address } [ preference preference-value ] [ tag tag-value ] [ description description-text ] Use either method. By default, BFD control mode for a static route is not configured.
Configuring static route FRR A link or router failure on a path can cause packet loss and even routing loop. Static route fast reroute (FRR) enables fast rerouting to minimize the impact of link or node failures. Figure 1 Network diagram As shown in Figure 1, upon a link failure, FRR specifies a backup next hop by using a routing policy for routes matching the specified criteria. Packets are directed to the backup next hop to avoid traffic interruption.
Step Command Remarks • Method 1: 3. Configure static route FRR.
Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure static routes: # Configure a default route on Switch A. system-view [SwitchA] ip route-static 0.0.0.0 0.0.0.0 1.1.4.2 # Configure two static routes on Switch B. system-view [SwitchB] ip route-static 1.1.2.0 255.255.255.0 1.1.4.1 [SwitchB] ip route-static 1.1.3.0 255.255.255.0 1.1.5.6 # Configure a default route on Switch C. system-view [SwitchC] ip route-static 0.0.0.0 0.0.
C:\Documents and Settings\Administrator>ping 1.1.2.2 Pinging 1.1.2.2 with 32 bytes of data: Reply from 1.1.2.2: bytes=32 time=1ms TTL=126 Reply from 1.1.2.2: bytes=32 time=1ms TTL=126 Reply from 1.1.2.2: bytes=32 time=1ms TTL=126 Reply from 1.1.2.2: bytes=32 time=1ms TTL=126 Ping statistics for 1.1.2.
Switch C Vlan-int11 10.1.1.100/24 Vlan-int13 13.1.1.2/24 Configuration procedure 1. Configure IP addresses for the interfaces. (Details not shown.) 2. Configure static routes and BFD: # Configure static routes on Switch A and enable BFD control mode for the static route that traverses the Layer 2 switch.
display ip routing-table protocol static Summary Count : 1 Static Routing table Status : Summary Count : 1 Destination/Mask Proto Pre 120.1.1.0/24 Static 60 Cost NextHop Interface 0 12.1.1.2 Vlan10 Static Routing table Status : Summary Count : 0 The output shows that Switch A communicates with Switch B through VLAN-interface 10. Then the link over VLAN-interface 10 fails. # Display static routes on Switch A.
Figure 4 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure static routes and BFD: # Configure static routes on Switch A and enable BFD control mode for the static route that traverses Switch D. system-view [SwitchA] bfd multi-hop min-transmit-interval 500 [SwitchA] bfd multi-hop min-receive-interval 500 [SwitchA] bfd multi-hop detect-multiplier 9 [SwitchA] ip route-static 120.1.1.0 24 2.2.2.9 bfd control-packet bfd-source 1.1.1.
Total Session Num: 1 Up Session Num: 1 Init Mode: Active IPv4 Session Working Under Ctrl Mode: LD/RD SourceAddr DestAddr State Holdtime Interface 4/7 1.1.1.9 2.2.2.9 Up 2000ms Loop1 The output shows that the BFD session has been created. # Display the static routes on Switch A. display ip routing-table protocol static Summary Count : 1 Static Routing table Status : Summary Count : 1 Destination/Mask Proto Pre 120.1.1.0/24 Static 60 Cost NextHop Interface 0 12.
Static route FRR configuration example Network requirements As shown in Figure 5, configure static routes on Switch S, Switch A, and Switch D, and configure static route FRR so when Link A becomes unidirectional, traffic can be switched to Link B immediately. Figure 5 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2.
Cost: 0 Tag: 0 OrigTblID: 0x0 TableID: 0x2 NBRID: 0x26000002 AttrID: 0xffffffff Preference: 60 State: Active Adv OrigVrf: default-vrf OrigAs: 0 LastAs: 0 Neighbor: 0.0.0.0 Flags: 0x1008c OrigNextHop: 13.13.13.2 Label: NULL RealNextHop: 13.13.13.2 BkLabel: NULL BkNextHop: 12.12.12.2 Tunnel ID: Invalid Interface: Vlan-interface200 BkTunnel ID: Invalid BkInterface: Vlan-interface100 # Display route 1.1.1.1/32 on Switch D to view the backup next hop information. [SwitchD] display ip routing-table 1.
Configuring a default route A default route is used to forward packets that do not match any specific routing entry in the routing table. Without a default route, packets that do not match any routing entries are discarded. A default route can be configured in either of the following ways: • The network administrator can configure a default route with both destination and mask being 0.0.0.0. For more information, see "Configuring a static route.
Configuring RIP Routing Information Protocol (RIP) is a distance-vector IGP suited to small-sized networks. It employs UDP to exchange route information through port 520. Overview RIP uses a hop count to measure the distance to a destination. The hop count from a router to a directly connected network is 0. The hop count from a router to a directly connected router is 1. To limit convergence time, RIP restricts the metric range from 0 to 15.
RIP operation RIP works as follows: 1. RIP sends request messages to neighboring routers. Neighboring routers return response messages that contain their routing tables. 2. RIP uses the received responses to update the local routing table and sends triggered update messages to its neighbors. All RIP routers on the network do this to learn latest routing information. 3. RIP periodically sends the local routing table to its neighbors.
RFC 2453, RIP Version 2 • RIP configuration task list Tasks at a glance Configuring basic RIP: • (Required.) Enabling RIP • (Optional.) Controlling RIP reception and advertisement on interfaces • (Optional.) Configuring a RIP version (Optional.
If you configure RIP settings in interface view before enabling RIP, the settings do not take effect until RIP is enabled. If a physical interface is attached to multiple networks, you cannot advertise these networks in different RIP processes. To enable RIP: Step Command Remarks 1. Enter system view. system-view N/A 2. Create a RIP process and enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] By default, no RIP process is enabled. 3.
configured, the interface sends RIPv1 broadcasts, and can receive RIPv1 broadcasts and unicasts, and RIPv2 broadcasts, multicasts, and unicasts. To configure a RIP version: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Specify a global RIP version.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Specify an inbound additional routing metric. rip metricin [ route-policy route-policy-name ] value The default setting is 0. 4. Specify an outbound additional routing metric. rip metricout [ route-policy route-policy-name ] value The default setting is 1.
Step Command Remarks 2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Disable RIPv2 automatic route summarization. undo summary By default, RIPv2 automatic route summarization is enabled. 4. Return to system view. quit N/A 5. Enter interface view. interface interface-type interface-number N/A 6. Configure a summary route. rip summary-address ip-address { mask | mask-length } By default, no summary route is configured.
Step Command Remarks 5. Enter interface view. interface interface-type interface-number N/A 6. Configure the RIP interface to advertise a default route. rip default-route { { only | originate } [ cost cost ] | no-originate } By default, a RIP interface can advertise a default route if the RIP process is enabled to advertise a default route. NOTE: The router enabled to advertise a default route does not accept default routes from RIP neighbors.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Configure a preference for RIP. preference [ route-policy route-policy-name ] value The default setting is 100. Configuring RIP route redistribution Perform this task to configure RIP to redistribute routes from other routing protocols, including OSPF, IS-IS, BGP, static, and direct. To configure RIP route redistribution: Step Command Remarks 1.
Suppress timer—Specifies how long a RIP route stays in suppressed state. When the metric of a • route is 16, the route enters the suppressed state. A suppressed route can be replaced by an updated route that is received from the same neighbor before the suppress timer expires and has a metric less than 16. Garbage-collect timer—Specifies the interval from when the metric of a route becomes 16 to when • it is deleted from the routing table. RIP advertises the route with a metric of 16.
Enabling poison reverse Poison reverse allows RIP to send routes through the interface where the routes were learned, but the metric of these routes is always set to 16 (unreachable) to avoid routing loops between neighbors. To enable poison reverse: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Enable poison reverse. rip poison-reverse By default, poison reverse is disabled.
Step Command Remarks 2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Enable zero field check on incoming RIPv1 messages. checkzero The default setting is enabled. Enabling source IP address check on incoming RIP updates Perform this task to enable source IP address check on incoming RIP updates. Upon receiving a message on an Ethernet interface, RIP compares the source IP address of the message with the IP address of the interface.
Configuring the RIP packet sending rate Perform this task to specify the interval for sending RIP packets and the maximum number of RIP packets that can be sent at each interval. This feature can avoid excessive RIP packets from affecting system performance and consuming too much bandwidth. To configure the RIP packet sending rate: Step Command… Remarks 1. Enter system view. system-view N/A 2. Enter RIP view. rip [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3.
Configuring BFD for RIP RIP detects route failures by periodically sending requests. If it receives no response for a route within a certain time, RIP considers the route unreachable. This detection mechanism is not fast enough. To speed up convergence, perform this task to enable BFD for RIP. For more information about BFD, see High Availability Configuration Guide. BFD provides only single-hop echo detection mode for directly connected RIP neighbors.
RIP FRR is available only when the state of primary link (with Layer 3 interfaces staying up) changes • from bidirectional to unidirectional or when the primary link fails. A unidirectional link refers to the link through which packets are forwarded only from one end to the other. Configuration prerequisites You must specify a next hop by using the apply fast-reroute backup-interface command in a routing policy and reference the routing policy for FRR.
RIP configuration examples Configuring basic RIP Network requirements As shown in Figure 7, enable RIPv2 on all interfaces on Router A and Router B. Configure Switch B to not advertise route 10.2.1.0/24 to Switch A, and to accept only route 2.1.1.0/24 from Switch A. Figure 7 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure basic RIP: # Configure Switch A. system-view [SwitchA] rip [SwitchA-rip-1] network 192.168.1.
# Configure RIPv2 on Switch A. [SwitchA] rip [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] quit # Configure RIPv2 on Switch B. [SwitchB] rip [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary [SwitchB-rip-1] quit # Display the RIP routing table on Switch A. [SwitchA] display rip 1 route Route Flags: R - RIP A - Aging, S - Suppressed, G - Garbage-collect ---------------------------------------------------------------------------- Peer 192.168.1.
A - Aging, S - Suppressed, G - Garbage-collect ---------------------------------------------------------------------------Peer 192.168.1.2 on Vlan-interface100 Destination/Mask Nexthop Cost Tag Flags Sec 10.1.1.0/24 192.168.1.2 1 0 RA 19 # Display the RIP routing table on Switch B. [SwitchB] display rip 1 route Route Flags: R - RIP A - Aging, S - Suppressed, G - Garbage-collect ---------------------------------------------------------------------------Peer 192.168.1.
system-view [SwitchB] rip 100 [SwitchB-rip-100] network 11.0.0.0 [SwitchB-rip-100] version 2 [SwitchB-rip-100] undo summary [SwitchB-rip-100] quit [SwitchB] rip 200 [SwitchB-rip-200] network 12.0.0.0 [SwitchB-rip-200] version 2 [SwitchB-rip-200] undo summary [SwitchB-rip-200] quit # Enable RIP 200, and configure RIPv2 on Switch C. system-view [SwitchC] rip 200 [SwitchC-rip-200] network 12.0.0.0 [SwitchC-rip-200] network 16.0.0.
Destinations : 15 Routes : 15 Destination/Mask Proto 0.0.0.0/32 10.2.1.0/24 Pre Cost NextHop Interface Direct 0 0 127.0.0.1 InLoop0 RIP 100 1 12.3.1.1 Vlan200 11.1.1.0/24 RIP 100 1 12.3.1.1 Vlan200 12.3.1.0/24 Direct 0 0 12.3.1.2 Vlan200 12.3.1.0/32 Direct 0 0 12.3.1.2 Vlan200 12.3.1.2/32 Direct 0 0 127.0.0.1 InLoop0 12.3.1.255/32 Direct 0 0 12.3.1.2 Vlan200 16.4.1.0/24 Direct 0 0 16.4.1.1 Vlan400 16.4.1.0/32 Direct 0 0 16.4.1.1 Vlan400 16.4.1.
[SwitchA] rip 1 [SwitchA-rip-1] network 1.0.0.0 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] quit # Configure Switch B. system-view [SwitchB] rip 1 [SwitchB-rip-1] network 1.0.0.0 [SwitchB-rip-1] version 2 [SwitchB-rip-1] undo summary # Configure Switch C. system-view [SwitchB] rip 1 [SwitchC-rip-1] network 1.0.0.0 [SwitchC-rip-1] version 2 [SwitchC-rip-1] undo summary # Configure Switch D. system-view [SwitchD] rip 1 [SwitchD-rip-1] network 1.0.0.
1.0.0.0/8, cost 0, auto-summary 1.1.1.0/24, cost 0, nexthop 1.1.1.1, RIP-interface 1.1.2.0/24, cost 0, nexthop 1.1.2.1, RIP-interface 1.1.3.0/24, cost 1, nexthop 1.1.1.2 1.1.4.0/24, cost 2, nexthop 1.1.1.2 1.1.5.0/24, cost 2, nexthop 1.1.1.2 The output shows that only one RIP route reaches network 1.1.5.0/24, with the next hop as Switch B (1.1.1.2) and a cost of 2.
[SwitchB] ospf [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] network 10.6.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] quit # Configure Switch C. system-view [SwitchC] ospf [SwitchC-ospf-1] area 0 [SwitchC-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [SwitchC-ospf-1-area-0.0.0.0] quit [SwitchC-ospf-1] quit 3. Configure basic RIP: # Configure Switch C.
4. 11.4.1.2/32 Direct 0 0 127.0.0.1 InLoop0 127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0 127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0 127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0 127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0 Configure route summarization: # Configure route summarization on Switch C and advertise only the summary route 10.0.0.0/8. [SwitchC] interface vlan-interface 300 [SwitchC-Vlan-interface300] rip summary-address 10.0.0.0 8 # Display the IP routing table on Switch D.
Figure 11 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure basic RIP: # Configure Switch A. system-view [SwitchA] rip 1 [SwitchA-rip-1] version 2 [SwitchA-rip-1] undo summary [SwitchA-rip-1] network 192.168.1.
[SwitchC-rip-1] network 192.168.1.0 [SwitchC-rip-1] network 192.168.3.0 [SwitchC-rip-1] import-route static [SwitchC-rip-1] quit Configure BFD parameters on VLAN-interface 100 of Switch A. 3. [SwitchA] bfd session init-mode active [SwitchA] bfd echo-source-ip 11.11.11.
The output shows that Switch A communicates with Switch C through VLAN-interface 100. Then the link over VLAN-interface 100 fails. # Display RIP routes destined for 120.1.1.0/24 on Switch A. display ip routing-table 120.1.1.0 24 verbose Summary Count : 1 Destination: 120.1.1.
# Configure Switch S. system-view [SwitchS] bfd echo-source-ip 1.1.1.1 [SwitchS] ip prefix-list abc index 10 permit 4.4.4.4 32 [SwitchS] route-policy frr permit node 10 [SwitchS-route-policy-frr-10] if-match ip address prefix-list abc [SwitchS-route-policy-frr-10] apply fast-reroute backup-interface vlan-interface 100 backup-nexthop 12.12.12.2 [SwitchS-route-policy-frr-10] quit [SwitchS] rip 1 [SwitchS-rip-1] fast-reroute route-policy frr [SwitchS-rip-1] quit # Configure Switch D.
Summary Count : 1 Destination: 1.1.1.1/32 Protocol: RIP SubProtID: 0x1 Cost: 1 Tag: 0 OrigTblID: 0x0 TableID: 0x2 NBRID: 0x26000002 AttrID: 0xffffffff Process ID: 1 Age: 04h20m37s Preference: 100 State: Active Adv OrigVrf: default-vrf OrigAs: 0 LastAs: 0 Neighbor: 13.13.13.1 Flags: 0x1008c OrigNextHop: 13.13.13.1 Label: NULL RealNextHop: 13.13.13.1 BkLabel: NULL BkNextHop: 24.24.24.
Configuring OSPF Open Shortest Path First (OSPF) is a link-state IGP developed by the OSPF working group of the IETF. OSPF version 2 is used for IPv4. OSPF refers to OSPFv2 throughout this chapter. Overview OSPF offers the following features: • Wide scope—Supports various network sizes and up to several hundred routers in an OSPF routing domain. • Fast convergence—Advertises routing updates instantly upon network topology changes.
• Link state acknowledgment (LSAck)—Acknowledges received LSU packets. It contains the headers of received LSAs (an LSAck packet can acknowledge multiple LSAs). LSA types OSPF advertises routing information in Link State Advertisements (LSAs). The following LSAs are commonly used: • Router LSA—Type-1 LSA, originated by all routers and flooded throughout a single area only. This LSA describes the collected states of the router's interfaces to an area.
Figure 13 Area-based OSPF network partition Area 4 Area 1 Area 0 Area 2 Area 3 Backbone area and virtual links Each AS has a backbone area that distributes routing information between non-backbone areas. Routing information between non-backbone areas must be forwarded by the backbone area. OSPF includes the following requirements: • All non-backbone areas must maintain connectivity to the backbone area. • The backbone area must maintain connectivity within itself.
Virtual links can also be used to provide redundant links. If the backbone area cannot maintain internal connectivity due to the failure of a physical link, you can configure a virtual link to replace the failed physical link, as shown in Figure 15. Figure 15 Virtual link application 2 Area 1 Virtual link R2 R1 Area 0 The virtual link between the two ABRs acts as a point-to-point connection.
Figure 16 NSSA area Router types OSPF routers are classified into the following types based on their positions in the AS: • Internal router—All interfaces on an internal router belong to one OSPF area. • ABR—Belongs to more than two areas, one of which must be the backbone area. ABR connects the backbone area to a non-backbone area. An ABR and the backbone area can be connected through a physical or logical link.
Route types OSPF prioritizes routes into the following route levels: • Intra-area route • Inter-area route • Type-1 external route • Type-2 external route The intra-area and inter-area routes describe the network topology of the AS. The external routes describe routes to external ASs. A Type-1 external route has high credibility.
• P2MP—No link is P2MP type by default. P2MP must be a conversion from other network types such as NBMA. On a P2MP network, OSPF packets are multicast to 224.0.0.5. • P2P—If the link layer protocol is PPP or HDLC, OSPF considers the network type as P2P. On a P2P network, OSPF packets are multicast to 224.0.0.5. The following are the differences between NBMA and P2MP networks: • NBMA networks are fully meshed. P2MP networks are not required to be fully meshed.
Figure 18 DR and BDR in a network DR DR other BDR DR other Physical links DR other Adjacencies NOTE: In OSPF, "neighbor" and "adjacency" are different concepts. After startup, OSPF sends a hello packet on each OSPF interface. A receiving router checks parameters in the packet. If the parameters match its own, the receiving router considers the sending router an OSPF neighbor.
OSPF configuration task list To run OSPF, you must first enable OSPF on the router. Make a proper configuration plan to avoid incorrect settings that can result in route blocking and routing loops. To configure OSPF, perform the following tasks: Tasks at a glance (Required.) Enabling OSPF (Optional.) Configuring OSPF areas: • Configuring a stub area • Configuring an NSSA area • Configuring a virtual link (Optional.
Tasks at a glance (Optional.
You can also specify a router ID when you create an OSPF process. If you specify a router ID when you create an OSPF process, any two routers in an AS must have • different router IDs. A common practice is to specify the IP address of an interface as the router ID. If you specify no router ID when you create the OSPF process, the global router ID is used. HP • recommends specifying a router ID when you create the OSPF process.
Configuring OSPF areas Before you configure an OSPF area, complete the following tasks: • Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. • Enable OSPF. Configuring a stub area You can configure a non-backbone area at an AS edge as a stub area. To do so, issue the stub command on all routers attached to the area. The routing table size is reduced because Type-5 LSAs will not be flooded within the stub area.
To configure a totally NSSA area, configure the nssa command on all the routers attached to the area and configure the nssa no-summary command on the ABR. The ABR of a totally NSSA area does not advertise inter-area routes into the area. To configure an NSSA area: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Enter area view. area area-id N/A 4.
Configuring OSPF network types OSPF classifies networks into the following types based on the link layer protocol: Broadcast—When the link layer protocol is Ethernet or FDDI, OSPF classifies the network type as • broadcast by default. NBMA—When the link layer protocol is Frame Relay, ATM, or X.25, OSPF classifies the network • type as NBMA by default. P2P—When the link layer protocol is PPP, LAPB, or HDLC, OSPF classifies the network type as P2P • by default.
Step 4. (Optional.) Configure a router priority for the interface. Command Remarks ospf dr-priority priority The default router priority is 1. Configuring the NBMA network type for an interface After you configure the network type as NBMA, you must specify neighbors and their router priorities because NBMA interfaces cannot find neighbors by broadcasting hello packets. To configure the NBMA network type for an interface: Step Command Remarks 1. Enter system view. system-view N/A 2.
Step Command Remarks By default, the network type of an interface depends on the link layer protocol. After you configure the OSPF network type for an interface as P2MP unicast, all packets are unicast over the interface. The interface cannot broadcast hello packets to discover neighbors, so you must manually specify the neighbors. Configure the OSPF network type for the interface as P2MP. ospf network-type p2mp [ unicast ] 4. Exit to system view. quit N/A 5. Enter OSPF view.
Configuring OSPF route summarization Configure route summarization on an ABR or ASBR to summarize contiguous networks into a single network and distribute it to other areas. Route summarization reduces the routing information exchanged between areas and the size of routing tables, and improves routing performance. For example, three internal networks 19.1.1.0/24, 19.1.2.0/24, and 19.1.3.0/24 are available within an area. You can summarize the three networks into network 19.1.0.
Configuring inbound OSPF route filtering Perform this task to filter routes calculated using received LSAs. The following filtering methods are available: • Use an ACL or IP prefix list to filter routing information by destination address. • Use the gateway keyword to filter routing information by next hop. • Use an ACL or IP prefix list to filter routing information by destination address and at the same time use the gateway keyword to filter routing information by next hop.
Configure a bandwidth reference value for the interface. OSPF computes the cost with this formula: • Interface OSPF cost = Bandwidth reference value (100 Mbps)/Interface bandwidth (Mbps). If the calculated cost is greater than 65535, the value of 65535 is used. If the calculated cost is less than 1, the value of 1 is used. If no cost or bandwidth reference value is configured for an interface, OSPF computes the interface cost based on the interface bandwidth and default bandwidth reference value.
Step 3. Configure the maximum number of ECMP routes. Command Remarks maximum load-balancing maximum By default, the maximum number of ECMP routes is the same as that configured in the max-ecmp-num command. For more information about the max-ecmp-num command, see IP Routing Command Reference. Configuring OSPF preference A router can run multiple routing protocols, and each protocol is assigned a preference.
Step 2. Enter OSPF view. Command Remarks ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Configure OSPF to redistribute routes from another routing protocol. import-route protocol [ process-id | all-processes | allow-ibgp ] [ cost cost | route-policy route-policy-name | tag tag | type type ] * 4. (Optional.) Configure OSPF to filter redistributed routes.
Step Configure the default parameters for redistributed routes (cost, upper limit, tag, and type). 3. Command Remarks default { cost cost | tag tag | type type } * By default, the cost is 1, the tag is 1, and the type is Type-2. Advertising a host route Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Enter area view. area area-id N/A 4. Advertise a host route.
LSA retransmission timer—Interval within which if the interface receives no acknowledgement • packets after sending a LSA to the neighbor, it retransmits the LSA. To configure OSPF timers: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A By default: • The hello interval on P2P and broadcast 3. Specify the hello interval. interfaces is 10 seconds.
Step 3. Specify the LSA transmission delay. Command Remarks ospf trans-delay seconds The default setting is 1 second. Specifying SPF calculation interval LSDB changes result in SPF calculations. When the topology changes frequently, a large amount of network and router resources are occupied by SPF calculation. You can adjust the SPF calculation interval to reduce the impact. When network changes are not frequent, the minimum-interval is adopted.
Specifying the LSA generation interval Adjust the LSA generation interval to protect network resources and routers from being overwhelmed by LSAs at the time of frequent network changes. When network changes are not frequent, LSAs are generated at the minimum-interval. If network changes become frequent, the LSA generation interval is incremented by incremental-interval × 2n-2 (n is the number of generation times) each time a LSA generation occurs until the maximum-interval is reached.
Configuring stub routers A stub router is used for traffic control. It reports its status as a stub router to neighboring OSPF routers. The neighboring routers do not use the stub router to forward data although they have a route to it. Router LSAs from the stub router might contain different link type values. A value of 3 means a link to a stub network, and the cost of the link will not be changed. A value of 1, 2 or 4 means a point-to-point link, a link to a transit network, or a virtual link.
Step Command Remarks • Configure simple authentication: 8. Configure interface authentication mode. ospf authentication-mode simple { cipher cipher-string | plain plain-string } • Configure MD5 authentication: ospf authentication-mode { hmac-md5 | md5 } key-id { cipher cipher-string | plain plain-string } Use either method. By default, no interface authentication is configured.
To configure the OSPF exit overflow interval: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Configure the OSPF exit overflow interval. The default setting is 300 seconds. lsdb-overflow-interval interval The value of 0 indicates that OSPF does not exit overflow state.
Configuring OSPF network management OSPF network management allows you to save system resources by enabling trap generation to report important events and configuring the maximum number of output traps for a specific time period. To configure OSPF network management: Step Command Remarks 1. Enter system view. system-view N/A 2. Bind OSPF MIB to an OSPF process. ospf mib-binding process-id By default, OSPF MIB is bound to the process with the smallest process ID. 3. Enable OSPF trap generation.
Enabling OSPF ISPF When the topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT. To enable OSPF ISPF: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Enable OSPF ISPF. ispf enable By default, OSPF ISPF is enabled.
Step Command Remarks 4. Enable the IETF GR. graceful-restart ietf [ global | planned-only ] * By default, the IETF GR capability is disabled. 5. (Optional.) Configure GR interval. graceful-restart interval interval-value The default setting is 120 seconds. Configuring the non-IETF OSPF GR Restarter Step Command Remarks 1. Enter system view. system-view N/A 2. Enable OSPF and enter its view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enable OSPF and enter its view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 3. Enable the link-local signaling capability. enable link-local-signaling By default, the link-local signaling capability is disabled. 4. Enable the out-of-band re-synchronization capability. enable out-of-band-resynchronization By default, the out-of-band re-synchronization capability is disabled. 5. (Optional.
Step 3. Command Enable BFD bidirectional control detection. Remarks By default, BFD bidirectional control detection is disabled. ospf bfd enable Both ends of a BFD session must be on the same network segment and in the same area. Configuring single-hop echo detection Step Command Remarks 1. Enter system view. system-view N/A 2. Configure the source address of echo packets. bfd echo-source-ip ip-address By default, the source address of echo packets is not configured. 3.
Configuration prerequisites Before you configure OSPF FRR, complete the following tasks: • Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. • Enable OSPF. Configuration guidelines • Do not use FRR and BFD at the same time. Otherwise, FRR might fail to take effect. • Do not use the fast-reroute lfa command together with the vlink-peer. Configuring OSPF FRR to calculate a backup next hop using the LFA algorithm Step Command Remarks 1. Enter system view.
Step Command Remarks 1. Enter system view. system-view N/A 2. Configure the source address of echo packets. bfd echo-source-ip ip-address By default, the source address of echo packets is not configured. 3. Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] * N/A 4. Enable OSPF FRR to specify a backup next hop by using a routing policy. fast-reroute route-policy route-policy-name By default, OSPF FRR is not configured.
Task Command Reset an OSPF process. reset ospf [ process-id ] process [ graceful-restart ] Re-enable OSPF route redistribution. reset ospf [ process-id ] redistribution OSPF configuration examples These configuration examples only cover commands for OSPF configuration. Configuring basic OSPF Network requirements • Enable OSPF on all switches, and split the AS into three areas. • Configure Switch A and Switch B as ABRs. Figure 20 Network diagram Area 0 Switch A Switch B Vlan-int100 10.1.1.
system-view [SwitchB] router id 10.3.1.1 [SwitchB] ospf [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] quit [SwitchB-ospf-1] area 2 [SwitchB-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.2] quit [SwitchB-ospf-1] quit # Configure Switch C. system-view [SwitchC] router id 10.4.1.1 [SwitchC] ospf [SwitchC-ospf-1] area 1 [SwitchC-ospf-1-area-0.0.0.1] network 10.2.1.0 0.0.0.
Area 0.0.0.1 interface 10.2.1.1(Vlan-interface200)'s neighbors Router ID: 10.4.1.1 State: Full DR: 10.2.1.1 Address: 10.2.1.2 Mode: Nbr is Master BDR: 10.2.1.2 GR State: Normal Priority: 1 MTU: 0 Options is 0x02 (-|-|-|-|-|-|E|-) Dead timer due in 32 sec Neighbor is up for 06:03:12 Authentication Sequence: [ 0 ] Neighbor state change count: 5 # Display OSPF routing information on Switch A. [SwitchA] display ospf routing OSPF Process 1 with Router ID 10.2.1.
Reply from 10.4.1.1: bytes=56 Sequence=4 ttl=253 time=1 ms Reply from 10.4.1.1: bytes=56 Sequence=5 ttl=253 time=1 ms --- 10.4.1.1 ping statistics --5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 1/1/2 ms Configuring OSPF route redistribution Network requirements • Enable OSPF on all the switches. • Split the AS into three areas. • Configure Switch A and Router B as ABRs. • Configure Switch C as an ASBR to redistribute external routes (static routes).
OSPF Process 1 with Router ID 10.5.1.1 Routing Table to ABR and ASBR Type Destination Area Cost Nexthop RtType Intra 10.3.1.1 0.0.0.2 10 10.3.1.1 ABR Inter 10.4.1.1 0.0.0.2 22 10.3.1.1 ASBR # Display the OSPF routing table on Switch D. display ospf routing OSPF Process 1 with Router ID 10.5.1.1 Routing Tables Routing for Network Destination Cost Type NextHop AdvRouter Area 10.2.1.0/24 22 Inter 10.3.1.1 10.3.1.1 0.0.0.2 10.3.1.0/24 10 Transit 10.3.1.2 10.3.1.
Figure 22 Network diagram Vlan-int600 10.4.1.1/24 Vlan-int500 10.3.1.1/24 Vlan-int400 10.1.1.1/24 Vlan-int300 10.2.1.2/24 Switch E Switch D Vlan-int300 10.2.1.1/24 Vlan-int400 10.1.1.2/24 AS 100 Switch C Vlan-int200 11.1.1.2/24 EBGP Vlan-int200 11.1.1.1/24 Switch B Vlan-int100 11.2.1.1/24 Vlan-int100 11.2.1.2/24 AS 200 Switch A Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Enable OSPF: # Configure Switch A.
[SwitchC-ospf-1-area-0.0.0.0] quit [SwitchC-ospf-1] quit # Configure Switch D. system-view [SwitchD] router id 10.3.1.1 [SwitchD] ospf [SwitchD-ospf-1] area 0 [SwitchD-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [SwitchD-ospf-1-area-0.0.0.0] network 10.3.1.0 0.0.0.255 [SwitchD-ospf-1-area-0.0.0.0] quit # Configure Switch E. system-view [SwitchE] router id 10.4.1.1 [SwitchE] ospf [SwitchE-ospf-1] area 0 [SwitchE-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [SwitchE-ospf-1-area-0.
Destinations : 16 5. Destination/Mask Proto 0.0.0.0/32 Routes : 16 Pre Cost NextHop Interface Direct 0 0 127.0.0.1 InLoop0 10.1.1.0/24 OSPF 150 1 11.2.1.1 Vlan100 10.2.1.0/24 OSPF 150 1 11.2.1.1 Vlan100 10.3.1.0/24 OSPF 150 1 11.2.1.1 Vlan100 10.4.1.0/24 OSPF 150 1 11.2.1.1 Vlan100 11.2.1.0/24 Direct 0 0 11.2.1.2 Vlan100 11.2.1.0/32 Direct 0 0 11.2.1.2 Vlan100 11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0 11.2.1.255/32 Direct 0 0 11.2.1.2 Vlan100 127.0.0.
Configuring an OSPF stub area Network requirements • Enable OSPF on all switches, and split the AS into three areas. • Configure Switch A and Switch B as ABRs to forward routing information between areas. • Configure Switch D as the ASBR to redistribute static routes. • Configure Area 1 as a stub area to reduce advertised LSAs without influencing reachability. Figure 23 Network diagram Switch A Area 0 Switch B Vlan-int100 10.1.1.1/24 Vlan-int100 10.1.1.2/24 Vlan-int200 10.2.1.
OSPF Process 1 with Router ID 10.4.1.1 Routing Tables Routing for Network Destination Cost Type 10.2.1.0/24 3 10.3.1.0/24 7 10.4.1.0/24 10.5.1.0/24 10.1.1.0/24 NextHop AdvRouter Area Transit 10.2.1.2 10.2.1.1 0.0.0.1 Inter 10.2.1.1 10.2.1.1 0.0.0.1 3 Stub 10.4.1.1 10.4.1.1 0.0.0.1 17 Inter 10.2.1.1 10.2.1.1 0.0.0.1 5 Inter 10.2.1.1 10.2.1.1 0.0.0.1 Destination Cost Type Tag NextHop AdvRouter 3.1.2.0/24 1 Type2 1 10.2.1.1 10.5.1.
10.5.1.0/24 17 Inter 10.2.1.1 10.2.1.1 0.0.0.1 10.1.1.0/24 5 Inter 10.2.1.1 10.2.1.1 0.0.0.1 Total Nets: 6 Intra Area: 2 Inter Area: 4 ASE: 0 NSSA: 0 After the area where Switch C resides is configured as a stub area, a default route takes the place of the AS external route. # Configure the area as a totally stub area by filtering Type-3 LSAs out of the stub area. [SwitchA] ospf [SwitchA-ospf-1] area 1 [SwitchA-ospf-1-area-0.0.0.1] stub no-summary [SwitchA-ospf-1-area-0.0.0.
Figure 24 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. 2. Enable OSPF (see "Configuring basic OSPF"). 3. Configure Area 1 as an NSSA area: # Configure Switch A. system-view [SwitchA] ospf [SwitchA-ospf-1] area 1 [SwitchA-ospf-1-area-0.0.0.1] nssa default-route-advertise no-summary [SwitchA-ospf-1-area-0.0.0.1] quit [SwitchA-ospf-1] quit # Configure Switch C. system-view [SwitchC] ospf [SwitchC-ospf-1] area 1 [SwitchC-ospf-1-area-0.0.0.
Destination Cost Type NextHop AdvRouter Area 0.0.0.0/0 65536 Inter 10.2.1.1 10.2.1.1 0.0.0.1 10.2.1.0/24 65535 Transit 10.2.1.2 10.4.1.1 0.0.0.1 10.4.1.0/24 3 Stub 10.4.1.1 0.0.0.1 10.4.1.1 Total Nets: 3 Intra Area: 2 4. Inter Area: 1 ASE: 0 NSSA: 0 Configure route redistribution: # Configure Switch C to redistribute static routes. [SwitchC] ip route-static 3.1.3.1 24 10.4.1.
Figure 25 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Enable OSPF: # Configure Switch A. system-view [SwitchA] router id 1.1.1.1 [SwitchA] ospf [SwitchA-ospf-1] area 0 [SwitchA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.0] quit [SwitchA-ospf-1] quit # Configure Switch B. system-view [SwitchB] router id 2.2.2.2 [SwitchB] ospf [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0.
[SwitchD-ospf-1-area-0.0.0.0] quit [SwitchD-ospf-1] return # Display OSPF neighbor information of Switch A. [SwitchA] display ospf peer verbose OSPF Process 1 with Router ID 1.1.1.1 Neighbors Area 0.0.0.0 interface 192.168.1.1(Vlan-interface1)'s neighbors Router ID: 2.2.2.2 State: 2-Way Address: 192.168.1.2 Mode: None DR: 192.168.1.4 GR State: Normal Priority: 1 BDR: 192.168.1.
# Display neighbor information of Switch D. display ospf peer verbose OSPF Process 1 with Router ID 4.4.4.4 Neighbors Area 0.0.0.0 interface 192.168.1.4(Vlan-interface1)'s neighbors Router ID: 1.1.1.1 State: Full Address: 192.168.1.1 Mode:Nbr is DR: 192.168.1.4 Slave GR State: Normal Priority: 100 BDR: 192.168.1.3 MTU: 0 Options is 0x02 (-|-|-|-|-|-|E|-) Dead timer due in 31 sec Neighbor is up for 00:11:17 Authentication Sequence: [ 0 ] Router ID: 2.2.2.2 State: Full Address: 192.
Options is 0x02 (-|-|-|-|-|-|E|-) Dead timer due in 39 sec Neighbor is up for 00:01:40 Authentication Sequence: [ 0 ] Router ID: 2.2.2.2 State: 2-Way Address: 192.168.1.2 Mode: None DR: 192.168.1.1 GR State: Normal Priority: 0 BDR: 192.168.1.3 MTU: 0 Options is 0x02 (-|-|-|-|-|-|E|-) Dead timer due in 35 sec Neighbor is up for 00:01:44 Authentication Sequence: [ 0 ] Router ID: 3.3.3.3 State: Full Address: 192.168.1.3 Mode: Nbr is Slave DR: 192.168.1.
Configuring OSPF virtual links Network requirements Configure a virtual link between Switch B and Switch C to connect Area 2 to the backbone area. After configuration, Switch B can learn routes to Area 2. Figure 26 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Enable OSPF: # Configure Switch A. system-view [SwitchA] ospf 1 router-id 1.1.1.1 [SwitchA-ospf-1] area 0 [SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.
[SwitchC–ospf-1-area-0.0.0.2] quit [SwitchC-ospf-1] quit # Configure Switch D. system-view [SwitchD] ospf 1 router-id 4.4.4.4 [SwitchD-ospf-1] area 2 [SwitchD-ospf-1-area-0.0.0.2] network 10.3.1.0 0.0.0.255 [SwitchD-ospf-1-area-0.0.0.2] quit # Display the OSPF routing table of Switch B. [SwitchB] display ospf routing OSPF Process 1 with Router ID 2.2.2.2 Routing Tables Routing for Network Destination Cost Type AdvRouter Area 10.2.1.0/24 2 Transit 10.2.1.1 NextHop 3.3.3.3 0.0.0.1 10.1.
Intra Area: 2 Inter Area: 1 ASE: 0 NSSA: 0 The output shows that Switch B has learned the route 10.3.1.0/24 to Area 2. Configuring OSPF GR Network requirements • As shown in Figure 27, Switch A, Switch B, and Switch C that belong to the same AS and the same OSPF routing domain are GR capable. • Switch A acts as the non-IETF GR Restarter; Switch B and Switch C are the GR Helpers and re-synchronize their LSDB with Switch A through OOB communication of GR.
[SwitchC] ospf 100 [SwitchC-ospf-100] area 0 [SwitchC-ospf-100-area-0.0.0.0] network 192.1.1.0 0.0.0.255 [SwitchC-ospf-100-area-0.0.0.0] quit 3. Configure OSPF GR: # Configure Switch A as the non-IETF OSPF GR Restarter: enable the link-local signaling capability, the out-of-band re-synchronization capability, and non-IETF GR capability for OSPF process 100.
OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.2. %Oct 21 15:29:30:897 2011 SwitchA OSPF/5/OSPF_NBR_CHG: OSPF 100 Neighbor 192.1.1.3(Vlan-interface100) from Loading to Full. *Oct 21 15:29:30:897 2011 SwitchA OSPF/7/DEBUG: OSPF 100 deleted OOB Progress timer for neighbor 192.1.1.3. *Oct 21 15:29:30:911 2011 SwitchA OSPF/7/DEBUG: OSPF GR: Process 100 Exit Restart,Reason : DR or BDR change,for neighbor : 192.1.1.3. *Oct 21 15:29:30:911 2011 SwitchA OSPF/7/DEBUG: OSPF 100 deleted GR Interval timer.
Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Enable OSPF: # Configure Switch A. system-view [SwitchA] ospf [SwitchA-ospf-1] area 0 [SwitchA-ospf-1-area-0.0.0.0] network 192.168.0.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.0] network 121.1.1.0 0.0.0.255 [SwitchA-ospf-1-area-0.0.0.
[SwitchA] quit # Enable BFD on Switch B and configure BFD parameters. [SwitchB] bfd session init-mode active [SwitchB] interface vlan-interface 10 [SwitchB-Vlan-interface10] ospf bfd enable [SwitchB-Vlan-interface10] bfd min-transmit-interval 500 [SwitchB-Vlan-interface10] bfd min-receive-interval 500 [SwitchB-Vlan-interface10] bfd detect-multiplier 6 Verifying the configuration # Display the BFD information on Switch A.
Protocol: OSPF Process ID: 1 SubProtID: 0x1 Age: 04h20m37s Cost: 4 Preference: 10 Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NBRID: 0x26000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 0.0.0.0 Flags: 0x1008c OrigNextHop: 10.1.1.100 Label: NULL RealNextHop: 10.1.1.
[SwitchS] ospf 1 [SwitchS-ospf-1] fast-reroute lfa [SwitchS-ospf-1] quit # Configure Switch D. system-view [SwitchD] bfd echo-source-ip 4.4.4.4 [SwitchD] ospf 1 [SwitchD-ospf-1] fast-reroute lfa [SwitchD-ospf-1] quit { (Method 2.) Enable OSPF FRR to designate a backup next hop by using a routing policy. # Configure Switch S. system-view [SwitchS] bfd echo-source-ip 1.1.1.1 [SwitchS] ip prefix-list abc index 10 permit 4.4.4.
TableID: 0x2 NBRID: 0x26000002 AttrID: 0xffffffff OrigAs: 0 LastAs: 0 Neighbor: 0.0.0.0 Flags: 0x1008c OrigNextHop: 13.13.13.2 Label: NULL RealNextHop: 13.13.13.2 BkLabel: NULL BkNextHop: 12.12.12.2 Tunnel ID: Invalid Interface: Vlan-interface200 BkTunnel ID: Invalid BkInterface: Vlan-interface100 # Display route 1.1.1.1/32 on Switch D to view the backup next hop information. [SwitchD] display ip routing-table 1.1.1.1 verbose Summary Count : 1 Destination: 1.1.1.
4. Verify OSPF timers. The dead interval on an interface must be at least four times the hello interval. 5. On an NBMA network, use the peer ip-address command to manually specify the neighbor. 6. At least one interface must have a router priority higher than 0 on an NBMA or a broadcast network. Incorrect routing information Symptom OSPF cannot find routes to other areas. Analysis The backbone area must maintain connectivity to all other areas.
Configuring IS-IS This chapter describes how to configure IS-IS for IPv4 networks. Overview Intermediate System-to-Intermediate System (IS-IS) is a dynamic routing protocol designed by the ISO to operate on the connectionless network protocol (CLNP). IS-IS was modified and extended in RFC 1195 by the IETF for application in both TCP/IP and OSI reference models, called "Integrated IS-IS" or "Dual IS-IS." IS-IS is an IGP used within an AS. It uses the SPF algorithm for route calculation.
IS-IS address format NSAP As shown in Figure 30, an NSAP address comprises the Initial Domain Part (IDP) and the Domain Specific Part (DSP). The IDP is analogous to the network ID of an IP address, and the DSP is analogous to the subnet and host ID. The IDP includes the Authority and Format Identifier (AFI) and the Initial Domain Identifier (IDI). The DSP includes: • High Order Part of DSP (HO-DSP)—Identifies the area. • System ID—Identifies the host. • SEL—Identifies the type of service.
SEL The N-SEL, or the NSAP selector (SEL), is similar to the protocol identifier in IP. Different transport layer protocols correspond to different SELs. All SELs in IP are 00. Routing method The IS-IS address format identifies the area, so a Level-1 router can easily identify packets destined to other areas. IS-IS routers perform routing as follows: • A Level-1 router performs intra-area routing according to the system ID.
information. All the Level-2 and Level-1-2 routers must be contiguous to form the backbone of the IS-IS routing domain. Level-2 routers can establish neighbor relationships even if they are in different areas. • Level-1-2 router—A router with both Level-1 and Level-2 router functions is a Level-1-2 router. It can establish Level-1 neighbor relationships with Level-1 and Level-1-2 routers in the same area, and establish Level-2 neighbor relationships with Level-2 and Level-1-2 routers in different areas.
Figure 32 IS-IS topology 2 Area 3 Area 2 L1/L2 L1/L2 L1 L2 L2 Area 1 L2 L2 Area 5 Area 4 L1 L1/L2 L1 L1/L2 L1 L1 L1 Both the Level-1 and Level-2 routers use the SPF algorithm to generate the shortest path tree. Route leaking Level-2 and Level-1-2 routers form a Level-2 area. An IS-IS routing domain comprises only one Level-2 area and multiple Level-1 areas. A Level-1 area must connect to the Level-2 area rather than other Level-1 area.
DIS and pseudonodes IS-IS routers on a broadcast network must elect a DIS. The Level-1 and Level-2 DISs are elected separately. You can assign different priorities to a router for different level DIS elections. The higher the router priority, the more likely the router becomes the DIS. If multiple routers with the same highest DIS priority exist, the one with the highest SNPA (Subnetwork Point of Attachment) address (MAC address on a broadcast network) will be elected.
IS-IS PDUs PDU IS-IS PDUs are encapsulated into link layer frames. An IS-IS PDU has two parts, the headers and the variable length fields. The headers comprise the PDU common header and the PDU specific header. All PDUs have the same PDU common header. The specific headers vary by PDU type.
A PSNP only contains the sequence numbers of one or multiple latest received LSPs. It can acknowledge multiple LSPs at one time. When LSDBs are not synchronized, a PSNP is used to request missing LSPs from a neighbor. CLV The variable fields of PDU comprise multiple Code-Length-Value (CLV) triplets. Figure 35 CLV format Table 5 shows that different PDUs contain different CLVs. Codes 1 through 10 are defined in ISO 10589 (code 3 and 5 are not shown in the table), and others are defined in RFC 1195.
• RFC 2966, Domain-wide Prefix Distribution with Two-Level IS-IS • RFC 2973, IS-IS Mesh Groups • RFC 3277, IS-IS Transient Blackhole Avoidance • RFC 3358, Optional Checksums in ISIS • RFC 3373, Three-Way Handshake for IS-IS Point-to-Point Adjacencies • RFC 3567, Intermediate System to Intermediate System (IS-IS) Cryptographic Authentication • RFC 3719, Recommendations for Interoperable Networks using IS-IS • RFC 3786, Extending the Number of IS-IS LSP Fragments Beyond the 256 Limit • RFC 37
Tasks at a glance (Optional.) Enhancing IS-IS network security: • Configuring neighbor relationship authentication • Configuring area authentication • Configuring routing domain authentication (Optional.) Configuring IS-IS GR (Optional.) Configuring BFD for IS-IS (Optional.) Configuring IS-IS FRR Configuring basic IS-IS Configuration prerequisites Before the configuration, complete the following tasks: • Configure the link layer protocol.
Level-2) neighbor relationships, configure the circuit level for its interfaces as Level-1 (or Level-2) to limit neighbor relationship establishment. To configure the IS level and circuit level: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Specify the IS level. is-level { level-1 | level-1-2 | level-2 } By default, the IS level is Level-1-2. 4. Return to system view. quit N/A 5.
Configuring IS-IS route control Configuration prerequisites Before the configuration, complete the following tasks: • Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes. • Enable IS-IS. Configuring IS-IS link cost The IS-IS cost of an interface is determined in the following order: 1. IS-IS cost specified in interface view. 2. IS-IS cost specified in system view. The cost is applied to the interfaces associated with the IS-IS process. 3.
Step 6. (Optional.) Specify a cost for the IS-IS interface. Command Remarks isis cost value [ level-1 | level-2 ] By default, no cost for the interface is specified. Configuring a global IS-IS cost Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. (Optional.) Specify an IS-IS cost style.
Step 3. Configure a preference for IS-IS. Command Remarks preference { preference | route-policy route-policy-name } * The default setting is 15. Configuring the maximum number of ECMP routes Perform this task to implement load sharing over ECMP routes. To configure the maximum number of ECMP routes: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view.
Advertising a default route IS-IS cannot redistribute a default route to its neighbors. This task enables IS-IS to advertise a default route of 0.0.0.0/0 in an LSP to the same-level neighbors. Upon receiving the default route, the neighbors add it into their routing table. To advertise a default route: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Advertise a default route.
Configuring IS-IS route filtering You can use an ACL, IP prefix list, or routing policy to filter routes calculated using received LSPs and routes redistributed from other routing protocols. Filtering routes calculated from received LSPs IS-IS saves LSPs received from neighbors in the LSDB, uses the SPF algorithm to calculate the shortest path tree with itself as the root, and installs the routes to the IS-IS routing table. Perform this task to filter calculated routes.
To configure IS-IS route leaking: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Configure route leaking from Level-1 to Level-2. import-route isis level-1 into level-2 [ filter-policy { acl-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] * By default, IS-IS advertises routes from Level-1 to Level-2. 4. Configure route leaking from Level-2 to Level-1.
On a broadcast link, Level-1 and Level-2 hello packets are advertised separately. You must set a hello multiplier for each level. On a P2P link, Level-1 and Level-2 hello packets are advertised in P2P hello packets. You do not need to specify Level-1 or Level-2. To specify the IS-IS hello multiplier: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3.
Step Disable the interface from sending and receiving IS-IS packets. 3. Command Remarks isis silent By default, the interface can send and receive IS-IS packets. Enabling an interface to send small hello packets IS-IS messages cannot be fragmented at the IP layer because they are directly encapsulated in frames. Any two IS-IS neighboring routers must negotiate a common MTU. To avoid sending big hellos to save bandwidth, enable the interface to send small hello packets without CLVs.
If such a change occurs frequently, excessive LSPs are generated, consuming a large amount of router resources and bandwidth. To solve the problem, you can adjust the LSP generation interval. When network changes are not frequent, the minimum-interval is adopted. If network changes become frequent, the LSP generation interval is incremented by incremental-interval × 2n-2 (n is the number of calculation times) each time a generation occurs until the maximum-interval is reached.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Specify the maximum length of generated Level-1 LSPs or Level-2 LSPs. lsp-length originate size [ level-1 | level-2 ] By default, the maximum length of generated Level-1 LSPs or Level-2 LSPs is 1497 bytes. 4. Specify the maximum length of received LSPs. lsp-length receive size By default, the maximum length of received LSPs is 1497 bytes.
Controlling SPF calculation interval Based on the LSDB, an IS-IS router uses the SPF algorithm to calculate the shortest path tree with itself being the root, and uses the shortest path tree to determine the next hop to a destination network. By adjusting the SPF calculation interval, you can prevent bandwidth and router resources from being overconsumed due to frequent topology changes. When network changes are not frequent, the minimum-interval is adopted.
Setting the LSDB overload bit By setting the overload bit in sent LSPs, a router informs other routers of failures that make it unable to select routes and forward packets. When an IS-IS router cannot record the complete LSDB, for example, because of memory insufficiency, it will calculate wrong routes. To make troubleshooting easier, temporarily isolate the router from the IS-IS network by setting the overload bit. To set the LSDB overload bit: Step Command Remarks 1. Enter system view.
Configuring dynamic system ID to host name mapping Static system ID to host name mapping requires you to manually configure a mapping for each router in the network. When a new router is added to the network or a mapping must be modified, you must configure all routers manually. When you use dynamic system ID to host name mapping, you only need to configure a host name for each router in the network.
Enabling IS-IS ISPF When the network topology changes, Incremental Shortest Path First (ISPF) computes only the affected part of the SPT, instead of the entire SPT. To enable IS-IS ISPF: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 3. Enable IS-IS ISPF. ispf enable By default, IS-IS is disabled.
Configuring area authentication Area authentication prevents the router from installing routing information from untrusted routers into the Level-1 LSDB. The router encapsulates the authentication password in the specified mode in Level-1 packets (LSP, CSNP, and PSNP) and checks the password in received Level-1 packets. Routers in a common area must have the same authentication mode and password. To configure area authentication: Step Command Remarks 1. Enter system view. system-view N/A 2.
GR Helper—A neighbor of the GR Restarter. It assists the GR Restarter to complete the GR process. • By default, the device acts as the GR Helper. Configure IS-IS GR on the GR Restarter. GR Restarter uses the following timers: T1 timer—Specifies the times that GR Restarter can send a Restart TLV with the RR bit set. When • rebooted, the GR Restarter sends a Restart TLV with the RR bit set to its neighbor.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Enable IS-IS on an interface. isis enable [ process-id ] N/A 4. Enable BFD on an IS-IS interface. isis bfd enable By default, an IS-IS interface is not enabled with BFD. Configuring IS-IS FRR A link or router failure on a path can cause packet loss and routing loop.
Configuring IS-IS FRR to automatically calculate a backup next hop Step Command Remarks 1. Enter system view. system-view N/A 2. Configure the source address of echo packets. bfd echo-source-ip ip-address By default, the source address of echo packets is not configured. 3. Enter IS-IS view. isis [ process-id ] [ vpn-instance vpn-instance-name ] N/A 4. Enable IS-IS FRR to automatically calculate a backup next hop. fast-reroute auto By default, IS-IS FRR is disabled.
Task Command Display IS-IS LSDB information. display isis lsdb [ [ level-1 | level-2 ] | local | lsp-id lspid | [ lsp-name lspname ] | verbose ] * [ process-id ] Display the host name to system ID mapping table. display isis name-table [ process-id ] Display IS-IS neighbor information.
2. Configure IS-IS: # Configure Switch A. system-view [SwitchA] isis 1 [SwitchA-isis-1] is-level level-1 [SwitchA-isis-1] network-entity 10.0000.0000.0001.00 [SwitchA-isis-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] isis enable 1 [SwitchA-Vlan-interface100] quit # Configure Switch B. system-view [SwitchB] isis 1 [SwitchB-isis-1] is-level level-1 [SwitchB-isis-1] network-entity 10.0000.0000.0002.
Verifying the configuration # Display the IS-IS LSDB on each switch to verify the LSPs. [SwitchA] display isis lsdb Database information for IS-IS(1) --------------------------------Level-1 Link State Database --------------------------LSPID Seq Num Checksum Holdtime Length ATT/P/OL -------------------------------------------------------------------------0000.0000.0001.00-00* 0x00000004 0xdf5e 1096 68 0/0/0 0000.0000.0002.00-00 0x00000004 0xee4d 1102 68 0/0/0 0000.0000.0002.
0000.0000.0002.01-00 0x00000005 0xd2b3 1052 55 0/0/0 0000.0000.0003.00-00* 0x00000014 0x194a 1051 111 1/0/0 0000.0000.0003.01-00* 0x00000002 0xabdb 854 55 0/0/0 *-Self LSP, +-Self LSP(Extended), ATT-Attached, P-Partition, OL-Overload Level-2 Link State Database --------------------------LSPID Seq Num Checksum Holdtime Length ATT/P/OL -------------------------------------------------------------------------0000.0000.0003.00-00* 0x00000012 0xc93c 842 100 0/0/0 0000.0000.0004.
[SwitchC] display isis route Route information for IS-IS(1) ------------------------------ Level-1 IPv4 Forwarding Table ----------------------------- IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------192.168.0.0/24 10 NULL Vlan300 Direct D/L/- 10.1.1.0/24 10 NULL Vlan100 Direct D/L/- 10.1.2.
DIS election configuration example Network requirements As shown in Figure 38, Switches A, B, C, and D reside in IS-IS area 10 on a broadcast network (Ethernet). Switch A and Switch B are Level-1-2 switches, Switch C is a Level-1 switch, and Switch D is a Level-2 switch. Change the DIS priority of Switch A to make it elected as the Level-1-2 DIS router. Figure 38 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Enable IS-IS: # Configure Switch A.
[SwitchC-isis-1] network-entity 10.0000.0000.0003.00 [SwitchC-isis-1] is-level level-1 [SwitchC-isis-1] quit [SwitchC] interface vlan-interface 100 [SwitchC-Vlan-interface100] isis enable 1 [SwitchC-Vlan-interface100] quit # Configure Switch D. system-view [SwitchD] isis 1 [SwitchD-isis-1] network-entity 10.0000.0000.0004.
Interface information for IS-IS(1) ---------------------------------Interface: Vlan-interface100 Id IPv4.State IPv6.State MTU Type DIS 001 Up Down 1497 L1/L2 Yes/No # Display information about IS-IS interfaces on Switch D. [SwitchD] display isis interface Interface information for IS-IS(1) ---------------------------------- Interface: Vlan-interface100 Id IPv4.State IPv6.
Interface information for IS-IS(1) ---------------------------------Interface: Vlan-interface100 Id IPv4.State IPv6.State MTU Type DIS 001 Up Down 1497 L1/L2 Yes/Yes The output shows that after the DIS priority configuration, Switch A becomes the DIS for Level-1-2, and the pseudonode is 0000.0000.0001.01. # Display information about IS-IS neighbors and interfaces on Switch C. [SwitchC] display isis peer Peer information for IS-IS(1) ---------------------------System Id: 0000.0000.
001 Up Down 1497 L1/L2 No/No IS-IS route redistribution configuration example Network requirements As shown in Figure 39, Switch A, Switch B, Switch C, and Switch D reside in the same AS. They use IS-IS to interconnect. Switch A and Switch B are Level-1 routers, Switch D is a Level-2 router, and Switch C is a Level-1-2 router. Redistribute RIP routes into IS-IS on Switch D. Figure 39 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2.
[SwitchB-Vlan-interface200] quit # Configure Switch C. system-view [SwitchC] isis 1 [SwitchC-isis-1] network-entity 10.0000.0000.0003.
----------------------------- IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------10.1.1.0/24 10 NULL VLAN100 Direct D/L/- 10.1.2.0/24 10 NULL VLAN200 Direct D/L/- 192.168.0.
# Configure IS-IS to redistribute RIP routes on Switch D. [SwitchD-rip-1] quit [SwitchD] isis 1 [SwitchD–isis-1] import-route rip level-2 # Display IS-IS routing information on Switch C. [SwitchC] display isis route Route information for IS-IS(1) ------------------------------ Level-1 IPv4 Forwarding Table ----------------------------- IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags ------------------------------------------------------------------------------10.1.1.
Figure 40 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure basic IS-IS: # Configure Switch A. system-view [SwitchA] isis 1 [SwitchA-isis-1] network-entity 10.0000.0000.0001.00 [SwitchA-isis-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] isis enable 1 [SwitchA-Vlan-interface100] quit # Configure Switch B. system-view [SwitchB] isis 1 [SwitchB-isis-1] network-entity 10.0000.0000.0002.
[SwitchC-Vlan-interface300] isis enable 1 [SwitchC-Vlan-interface300] quit # Configure Switch D. system-view [SwitchD] isis 1 [SwitchD-isis-1] network-entity 20.0000.0000.0001.00 [SwitchD-isis-1] quit [SwitchD] interface vlan-interface 300 [SwitchD-Vlan-interface300] isis enable 1 [SwitchD-Vlan-interface300] quit 3.
[SwitchC-isis-1] quit 5. Configure routing domain authentication mode as MD5 and set the plaintext password to 1020Sec on Switch C and Switch D. [SwitchC] isis 1 [SwitchC-isis-1] domain-authentication-mode md5 plain 1020Sec [SwitchC-isis-1] quit [SwitchD] isis 1 [SwitchD-isis-1] domain-authentication-mode md5 plain 1020Sec IS-IS GR configuration example Network requirements As shown in Figure 41, Switch A, Switch B, and Switch C belong to the same IS-IS routing domain.
reset isis all 1 graceful-restart Reset IS-IS process? [Y/N]:y # Check the GR status of IS-IS on Switch A.
Switch C Vlan-int11 11.1.1.1/24 Vlan-int11 11.1.1.2/24 Vlan-int13 13.1.1.2/24 Vlan-int13 Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure basic IS-IS: # Configure Switch A. system-view [SwitchA] isis [SwitchA-isis-1] network-entity 10.0000.0000.0001.
[SwitchA-Vlan-interface10] bfd min-receive-interval 500 [SwitchA-Vlan-interface10] bfd min-transmit-interval 500 [SwitchA-Vlan-interface10] bfd detect-multiplier 7 # Enable BFD and configure BFD parameters on Switch B.
Summary Count : 1 Destination: 120.1.1.0/24 Protocol: ISIS Process ID: 1 SubProtID: 0x1 Age: 04h20m37s Cost: 20 Preference: 10 Tag: 0 State: Active Adv OrigTblID: 0x0 OrigVrf: default-vrf TableID: 0x2 OrigAs: 0 NBRID: 0x26000002 LastAs: 0 AttrID: 0xffffffff Neighbor: 0.0.0.0 Flags: 0x1008c OrigNextHop: 10.1.1.100 Label: NULL RealNextHop: 10.1.1.
system-view [SwitchS] bfd echo-source-ip 1.1.1.1 [SwitchS] isis 1 [SwitchS-isis-1] fast-reroute auto [SwitchS-isis-1] quit # Configure Switch D. system-view [SwitchD] bfd echo-source-ip 4.4.4.4 [SwitchD] isis 1 [SwitchD-isis-1] fast-reroute auto [SwitchD-isis-1] quit { (Method 2.) Enable IS-IS FRR to designate a backup next hop by using a referenced routing policy: # Configure Switch S. system-view [SwitchS] bfd echo-source-ip 1.1.1.
Cost: 10 Tag: 0 OrigTblID: 0x0 TableID: 0x2 NBRID: 0x26000002 AttrID: 0xffffffff Preference: 10 State: Active Adv OrigVrf: default-vrf OrigAs: 0 LastAs: 0 Neighbor: 0.0.0.0 Flags: 0x1008c OrigNextHop: 13.13.13.2 Label: NULL RealNextHop: 13.13.13.2 BkLabel: NULL BkNextHop: 12.12.12.2 Tunnel ID: Invalid Interface: Vlan-interface200 BkTunnel ID: Invalid BkInterface: Vlan-interface100 # Display route 1.1.1.1/32 on Switch D to view the backup next hop information.
Configuring BGP Overview Border Gateway Protocol (BGP) is an exterior gateway protocol (EGP). It is called internal BGP (IBGP) when it runs within an AS and called external BGP (EBGP) when it runs between ASs. The current version in use is BGP-4 (RFC 4271). BGP has the following characteristics: • Focuses on route control and selection rather than route discovery and calculation. • Uses TCP to enhance reliability.
• Keepalive—BGP sends Keepalive messages between peers to maintain connectivity. • Route-refresh—BGP sends a Route-refresh message to request the routing information of a specified address family from a peer. • Notification—BGP sends a Notification message upon detecting an error and immediately closes the connection. BGP path attributes BGP uses the following path attributes in update messages for route filtering and selection: • ORIGIN The ORIGIN attribute specifies the origin of BGP routes.
Figure 44 AS_PATH attribute BGP uses the AS_PATH attribute to implement the following functions: { Avoid routing loops—A BGP router does not receive routes containing the local AS number to avoid routing loops. { Affect route selection—BGP gives priority to the route with the shortest AS_PATH length if other factors are the same. As shown in Figure 44, the BGP router in AS 50 gives priority to the route passing AS 40 for sending data to the destination 8.0.0.0.
Figure 45 NEXT_HOP attribute • MED (Multi-Exit Discriminator) BGP advertises the MED attribute between two neighboring ASs, each of which does not advertise the attribute to any other AS. Similar to metrics used by IGPs, MED is used to determine the best route for traffic going into an AS.
Generally BGP only compares MEDs of routes received from the same AS. You can also use the compare-different-as-med command to force BGP to compare MED values of routes received from different ASs. • LOCAL_PREF The LOCAL_PREF attribute is exchanged between IBGP peers only, and is not advertised to any other AS. It indicates the priority of a BGP router. BGP uses LOCAL_PREF to determine the best route for traffic leaving the local AS.
{ NO_EXPORT—Routes with this attribute cannot be advertised out of the local AS or out of the local confederation, but can be advertised to other sub-ASs in the confederation. For confederation information, see "Settlements for problems in large-scale BGP networks." { No_ADVERTISE—Routes with this attribute cannot be advertised to other BGP peers. { No_EXPORT_SUBCONFED—Routes with this attribute cannot be advertised out of the local AS or other sub-ASs in the local confederation.
BGP route advertisement rules BGP follow these rules for route advertisement: • When multiple feasible routes to a destination exist, BGP advertises only the best route to its peers. If the advertise-rib-active command is configured, BGP advertises the best route in the IP routing table; if not, BGP advertise the best route in the BGP routing table. • BGP advertises only routes that it uses. • BGP advertises routes learned from an EBGP peer to all BGP peers, including both EBGP and IBGP peers.
Figure 48 Network diagram In Figure 48, Router A and Router B are IBGP peers of Router C. Router D and Router E both advertise a route 9.0.0.0 to Router C. If load balancing with a maximum number of two routes is configured on Router C, and the two routes have the same AS_PATH, ORIGIN, LOCAL_PREF, and MED, Router C installs both the two routes to its routing table for load balancing.
BGP route dampening uses a penalty value to judge the stability of a route. The bigger the value, the less stable the route. Each time a route state change (from reachable to unreachable) occurs, or a reachable route's attribute changes, BGP adds a penalty value (1000, which is a fixed number and cannot be changed) to the route. When the penalty value of the route exceeds the suppress value, the route is suppressed and cannot become the optimal route.
A router that is neither a route reflector nor a client is a non-client, which, as shown in Figure 50, must establish BGP sessions to the route reflector and other non-clients. Figure 50 Network diagram for a route reflector The route reflector and clients form a cluster. Typically a cluster has one route reflector. The ID of the route reflector is the Cluster_ID. You can configure more than one route reflector in a cluster to improve availability, as shown in Figure 51.
Confederation is another method to manage growing IBGP connections in an AS. It splits an AS into multiple sub-ASs. In each sub-AS, IBGP peers are fully meshed. As shown in Figure 52, intra-confederation EBGP connections are established between sub-ASs in AS 200. Figure 52 Confederation network diagram A non-confederation BGP speaker does not need to know sub-ASs in the confederation. It considers the confederation as one AS, and the confederation ID as the AS number.
• MP_UNREACH_NLRI—Carries unfeasible route prefixes for multiple network layer protocols. MP-BGP uses these two attributes to advertise feasible and unfeasible routes for different network layer protocols. BGP speakers not supporting MP-BGP ignore updates containing these attributes and do not forward them to its peers. The current MP-BGP implementation supports multiple protocol extensions, including VPN, IPv6, and multicast. For more information about VPN, see MPLS Configuration Guide.
View names BGP VPNv4 address family view Ways to enter the views Remarks system-view Configurations in this view are effective for VPNv4 routes. For information about BGP VPNv4 address family view, see MPLS Configuration Guide.
• RFC 2796, BGP Route Reflection • RFC 3065, Autonomous System Confederations for BGP • RFC 4271, A Border Gateway Protocol 4 (BGP-4) • RFC 4724, Graceful Restart Mechanism for BGP • RFC 4360, BGP Extended Communities Attribute • RFC 4760, Multiprotocol Extensions for BGP-4 BGP configuration task list In a basic BGP network, you only need to perform the following configurations: • Enable BGP. • Configure BGP peers or peer groups.
Tasks at a glance Remarks (Optional.
Tasks at a glance Remarks (Optional.) Controlling BGP path selection: • • • • • • Specifying a preferred value for routes received Configuring preferences for BGP routes N/A Configuring the default local preference Configuring the MED attribute Configuring the NEXT_HOP attribute Configuring the AS_PATH attribute (Optional.
To enable BGP: Step 1. 2. Enter system view. Configure a global router ID. Command Remarks system-view N/A router id router-id By default, no global router ID is configured, and BGP uses the highest loopback interface IP address—if any—as the router ID. If no loopback interface IP address is available, BGP uses the highest physical interface IP address as the route ID regardless of the interface status. By default, BGP is not enabled. • Enable BGP and enter BGP 3.
Step 6. Enable the router to exchange IPv4 unicast routing information with the specified peer. Command Remarks peer ip-address enable By default, the router cannot exchange IPv4 unicast routing information with the peer. Command Remarks system-view N/A Configuring an IPv6 BGP peer Step 1. Enter system view. • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Create an IBGP peer group. group group-name [ internal ] By default, no IBGP peer group is created. By default, no peer exists in the peer group. 4. Add a peer into the IBGP peer group. peer ip-address group group-name [ as-number as-number ] 5. (Optional.
Step 6. 7. Command Remarks Create and enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view. ipv6-family [ unicast ] By default, the BGP IPv6 unicast address family view and BGP-VPN IPv6 unicast address family view are not created. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group. peer group-name enable By default, the router cannot exchange IPv6 unicast routing information with the peers.
Step Command Remarks By default, no peer exists in the peer group. 5. Add a peer into the EBGP peer group. peer ip-address group group-name [ as-number as-number ] The as-number as-number option, if used, must specify the same AS number as the peer group-name as-number as-number command. 6. (Optional.) Configure a description for a peer group. peer group-name description description-text By default, no description is configured for the peer group. 7.
Step 8. Enable the router to exchange IPv6 unicast routing information with peers in the specified peer group. Command Remarks peer group-name enable By default, the router cannot exchange IPv6 unicast routing information with the peers. To configure an EBGP peer group by using Method 2 (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b.
Step Command Remarks 3. Create an EBGP peer group. group group-name external By default, no EBGP peer group is created. 4. Create an IPv6 BGP peer and specify its AS number. peer ipv6-address as-number as-number By default, no IPv6 BGP peer is created. By default, no peer exists in the peer group. 5. Add the peer into the EBGP peer group. peer ipv6-address group group-name [ as-number as-number ] 6. (Optional.) Configure a description for the peer group.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Create an EBGP peer group. group group-name external By default, no EBGP peer group is created. 4. Add a peer into the EBGP peer group. peer ipv6-address group group-name as-number as-number By default, no peer exists in the peer group. 5. (Optional.
Step Enter system view. 1. Command Remarks system-view N/A • Enter BGP view: bgp as-number Enter BGP view or BGP-VPN instance view. 2. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name Specify the source interface for establishing TCP connections to a peer or peer group. 3.
To inject a local network (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Inject a local network to the BGP routing table.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A 4. Enable route redistribution from the specified IGP into BGP.
Configuring BGP route summarization Route summarization can reduce the number of redistributed routes and the routing table size. IPv4 BGP supports automatic route summarization and manual route summarization. Manual summarization takes precedence over automatic summarization. IPv6 BGP supports only manual route summarization. The output interface of a BGP summary route is Null 0 on the originating router. Therefore, a summary route must not be an optimal route on the originating router.
Step 3. 4. Command Remarks Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Create a summary route in the BGP routing table. aggregate ip-address { mask | mask-length } [ as-set | attribute-policy route-policy-name | detail-suppressed | origin-policy route-policy-name | suppress-policy route-policy-name ] * By default, no summary route is configured. To configure BGP manual route summarization (IPv6): Step Command Remarks 1.
Advertising a default route to a peer or peer group Perform this task to advertise a default BGP route with the next hop being the advertising router to a peer or peer group. To advertise a default route to a peer or peer group (IPv4): Step Enter system view. 1. Command Remarks system-view N/A • Enter BGP view: bgp as-number Enter BGP view or BGP-VPN instance view. 2. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4.
You can specify a percentage threshold for the router to display an alarm message. When the ratio of the number of received routes to the maximum number reaches the percentage value, the router displays an alarm message. To limit routes that a router can receive from a peer or peer group (IPv4): Step Enter system view. 1. Command Remarks system-view N/A • Enter BGP view: bgp as-number Enter BGP view or BGP-VPN instance view. 2. • Enter BGP-VPN instance view: a. bgp as-number N/A b.
AS path list (see "Configuring routing policies") • Configuring BGP route distribution filtering policies To configure BGP route distribution filtering policies, use the following methods: • Use an ACL or prefix list to filter routing information advertised to all peers. • Use a routing policy, ACL, AS path list, or prefix list to filter routing information advertised to a peer or peer group. If you configure multiple filtering policies, apply them in the following sequence: 1.
Step Command Remarks • Reference an ACL or IP prefix list to filter routes redistributed to all peers: filter-policy { acl-number | prefix-list prefix-list-name } export [ direct | isis process-id | ospf process-id | rip process-id | static ] • Reference a routing policy to filter advertisements to a peer or peer group: peer { group-name | ip-address } route-policy route-policy-name export 4. Configure BGP route distribution filtering policies.
Step Command Remarks • Reference an ACL or IPv6 prefix list to filter routes redistributed to all peers: filter-policy { acl6-number | prefix-list ipv6-prefix-name } export [ direct | isisv6 process-id | ospfv3 process-id | ripng process-id | static ] • Reference a routing policy to filter advertisements to a peer or peer group: peer { group-name | ipv6-address } route-policy route-policy-name export 4. Configure BGP route distribution filtering policies.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view.
Step 3. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view. Command Remarks ipv6-family [ unicast ] N/A • Reference ACL or IPv6 prefix list to filter routes from all peers: filter-policy { acl6-number | prefix-list ipv6-prefix-name } import • Reference a routing policy to filter routing information from a peer or peer group: peer { group-name | ipv6-address } route-policy route-policy-name import • Reference an ACL to filter routing 4.
Step 4. Configure BGP route dampening. Command Remarks dampening [ half-life-reachable half-life-unreachable reuse suppress ceiling | route-policy route-policy-name ] * By default, BGP route dampening is not configured. To configure BGP route dampening (IPv6): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4.
Step 3. 4. Command Remarks Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Specify a preferred value for routes received from a peer or peer group. peer { group-name | ip-address } preferred-value value The default preferred value is 0. To specify a preferred value for routes from a peer or peer group (IPv6): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2.
Step Command Remarks • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A 4. Configure preferences for EBGP, IBGP, and local BGP routes.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Configure the default local preference. default local-preference value The default local preference is 100.
Step Command Remarks • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Configure the default MED value. default med med-value The default MED value is 0. To configure the default MED value (IPv6): Step 1. Enter system view.
Step Enable MED comparison for routes from different ASs. 4. Command Remarks compare-different-as-med By default, this feature is disabled. To enable MED comparison for routes from different ASs (IPv6): Step Command Remarks 1. Enter system view. system-view N/A 2. Enter BGP view. bgp as-number N/A 3. Enter BGP IPv6 unicast address family view. ipv6-family [ unicast ] N/A 4. Enable MED comparison for routes from different ASs.
NextHop MED *>i Network 10.0.0.0 1.1.1.1 60 0 200e * i 10.0.0.0 2.2.2.2 50 0 300e 3.3.3.3 50 0 200e * i LocPrf PrefVal Path/Ogn However, Router C and Router A reside in the same AS, and Router C has a greater MED, so network 10.0.0.0 learned from Router C should not be optimal. You can configure the bestroute compare-med command to enable MED comparison for routes from the same AS on Router D.
BGP does not compare the route with other routes. For example, a confederation has three AS numbers 65006, 65007, and 65009. BGP receives three routes from different confederation peers. The AS_PATH attributes of these routes are 65006 65009, 65007 65009, and 65008 65009, and the MED values of them are 2, 3, and 1. Because the third route's AS_PATH attribute contains AS number 65008 that does not belong to the confederation, BGP does not compare it with other routes.
Figure 54 NEXT_HOP attribute configuration If a BGP router has two peers on a broadcast network, it does not set itself as the next hop for routes sent to an EBGP peer by default. As shown in Figure 55, Router A and Router B establish an EBGP neighbor relationship, and Router B and Router C establish an IBGP neighbor relationship. They are on the same broadcast network 1.1.1.0/24. When Router B sends EBGP routes to Router A, it does not set itself as the next hop by default.
Step 4. Specify the router as the next hop for routes sent to a peer or peer group. Command Remarks peer { group-name | ip-address } next-hop-local By default, the router sets itself as the next hop for routes sent to an EBGP peer or peer group, but does not set itself as the next hop for routes sent to an IBGP peer or peer group. To configure the NEXT_HOP attribute (IPv6): Step Command Remarks 1. Enter system view. system-view N/A 2. Enter BGP view. bgp as-number N/A 3.
Step 4. Permit the local AS number to appear in routes from a peer or peer group and specify the appearance times. Command Remarks peer { group-name | ip-address } allow-as-loop [ number ] By default, the local AS number is not allowed in routes from a peer or peer group. To permit the local AS number to appear in routes from a peer or peer group and specify the appearance times (IPv6): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4. Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view. ipv6-family [ unicast ] N/A Disable BGP from considering AS_PATH during best route selection.
Step 3. Command Advertise a fake AS number to a peer or peer group. peer { group-name | ipv6-address } fake-as as-number Remarks By default, no fake AS number is advertised to a peer or peer group. This command applies to only EBGP peers or EBGP peer groups. Configuring AS number substitution IMPORTANT: Do not configure AS number substitution in normal circumstances. Otherwise, routing loops might occur.
To configure AS number substitution for a peer or peer group (IPv6): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Configure AS number substitution for a peer or peer group. peer { group-name | ipv6-address } substitute-as By default, AS number substitution is not configured.
Step Enter BGP IPv6 unicast address family view or BGP-VPN IPv6 unicast address family view. 3. Configure BGP to remove private AS numbers from the AS_PATH attribute of updates sent to an EBGP peer or peer group. 4. Command Remarks ipv6-family [ unicast ] N/A peer { group-name | ipv6-address } public-as-only By default, this feature is not configured. This command is only applicable to EBGP peers or peer groups.
To configure the keepalive interval and hold time (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name Use either approach. • Configure the global keepalive interval and hold time: timer keepalive keepalive hold holdtime 3. Configure the keepalive interval and hold time.
Configuring the interval for sending updates for the same route A BGP router sends an update message to its peers when a route is changed. If the route changes frequently, the BGP router keeps sending updates for the same route, resulting route flapping. To prevent this situation, perform this task to configure the interval for sending updates for the same route to a peer or peer group. To configure the interval for sending the same update to a peer or peer group (IPv4): Step 1. Enter system view.
Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Enable BGP to establish an EBGP session to an indirectly-connected peer or peer group and specify the maximum hop count.
Enabling 4-byte AS number suppression BGP supports 4-byte AS numbers. The 4-byte AS number occupies four bytes, in the range of 1 to 4294967295. By default, a device sends an Open message to the peer device for session establishment. The Open message indicates that the device supports 4-byte AS numbers. If the peer device does not support 4-byte AS numbers (supports only 2-byte AS numbers), the session cannot be established. To resolve this issue, enable the 4-byte AS number suppression function.
To configure the maximum number of ECMP routes (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. 4. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A Configure the maximum number of ECMP routes for load balancing.
Step Command Remarks • Enter BGP view: bgp as-number Enter BGP view or BGP-VPN instance view. 2. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name Disable BGP to establish a session to a peer or peer group. 3. peer { group-name | ip-address } ignore By default, BGP can establish a session to a peer or peer group. To disable BGP to establish a session to a peer or peer group (IPv6): Step 1. Enter system view.
This method requires that both the local router and the peer support route refresh. Enabling route-refresh To enable BGP route refresh for a peer or peer group (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b.
Step Command Remarks • Enable BGP route refresh for the specified peer or peer group: peer { group-name | ipv6-address } capability-advertise route-refresh 3. Enable BGP route refresh for a peer or peer group. • Enable BGP route refresh and multi-protocol extension capability for the specified peer or peer group: undo peer { group-name | ipv6-address } capability-advertise conventional Use either approach. By default, BGP route refresh is enabled.
Step 4. Command Save all route updates from the peer or peer group. peer { group-name | ipv6-address } keep-all-routes Remarks By default, the routes are not saved. This command takes effect only for the routes received after this command is executed. Configuring manual soft-reset To configure manual soft-reset (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a.
Step Command Remarks • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name • Enable BGP route refresh for the specified peer or peer group: peer { group-name | ipv6-address } capability-advertise route-refresh 3. 4. 5. By default, BGP route refresh is enabled. Enable BGP route refresh for a peer or peer group. • Enable BGP route refresh and Return to user view.
Step Command Remarks • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Configure BGP to protect EBGP peer or peer group when the memory usage reaches level 2 threshold. peer { group-name | ip-address } low-memory-exempt By default, BGP tears down an EBGP session to release memory resources periodically when level 2 threshold is reached.
To configure BGP community (IPv4): Step 1. Enter system view. Command Remarks system-view N/A • Enter BGP view: bgp as-number 2. Enter BGP view or BGP-VPN instance view. • Enter BGP-VPN instance view: a. bgp as-number N/A b. ip vpn-instance vpn-instance-name 3. Enter BGP IPv4 unicast address family view or BGP-VPN IPv4 unicast address family view. ipv4-family [ unicast ] N/A • Advertise the COMMUNITY 4. 5. Advertise the COMMUNITY or extended community attribute to a peer or peer group.
Step 5. (Optional.) Apply a routing policy to routes advertised to a peer or peer group. Command Remarks peer { group-name | ipv6-address } route-policy route-policy-name export By default, no routing policy is applied. Configuring a BGP route reflector If an AS has many BGP routers, configure them as a cluster. To reduce IBGP connections, configure one of them as a route reflector and others as clients. To improve availability, you can specify multiple route reflectors for a cluster.
Step Command Remarks 5. Enable route reflection between clients. reflect between-clients By default, route reflection between clients is enabled. 6. (Optional.) Configure the cluster ID of the route reflector. reflector cluster-id { cluster-id | ip-address } By default, a route reflector uses its own router ID as the cluster ID. Configuring a BGP confederation BGP confederation provides another way to reduce IBGP connections in an AS. A confederation contains sub-ASs.
Step Enable confederation compatibility. 3. Command Remarks confederation nonstandard By default, confederation compatibility is disabled. Configuring BGP GR GR ensures forwarding continuity when BGP restarts or an active/standby switchover occurs. Two routers are required to complete a GR process. The following are router roles in a GR process. • GR Restarter—Performs GR upon a BGP restart or active/standby switchover. • GR Helper—Helps the GR Restarter to complete the GR process.
Step Command Remarks 2. Enter BGP view. bgp as-number N/A 3. Enable GR capability for BGP. graceful-restart By default, GR capability is disabled for BGP. 4. Configure the GR timer. graceful-restart timer restart timer 5. Configure the maximum time to wait for the End-of-RIB marker. graceful-restart timer wait-for-rib timer The default setting is 150 seconds. The time that a peer waits to reestablish a session must be less than the hold time. The default setting is 180 seconds.
IMPORTANT: If you have enabled GR, use BFD with caution because BFD might detect a failure before the system performs GR, which will result in GR failure. If you have enabled both BFD and GR for BGP, do not disable BFD during a GR process to avoid GR failure. BGP maintains neighbor relationships based on the keepalive timer and hold timer in seconds. It requires that the hold time must be at least three times the keepalive interval. This mechanism makes link failure detection slow.
Task Command Display BGP IPv4 unicast peer group information. display bgp group ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ group-name ] Display BGP IPv4 unicast peer or peer group information. display bgp peer ipv4 [ unicast ] [ vpn-instance vpn-instance-name ] [ ip-address { log-info | verbose } | group-name log-info | verbose ] Display BGP IPv4 unicast routing information.
Execute display commands in any view and reset commands in user view (IPv6). Task Command Display BGP IPv6 unicast peer group information. display bgp group ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ group-name ] Display BGP IPv6 unicast peer or peer group information. Display BGP IPv6 unicast routing information. Display BGP IPv6 unicast routing information sent to/received from the specified BGP peer.
Task Command Clear BGP IPv6 unicast route flap information. reset bgp flap-info ipv6 [ unicast ] [ vpn-instance vpn-instance-name ] [ network-address prefix-length | as-path-acl as-path-acl-number | peer ipv6-address ] IPv4 BGP configuration examples Basic BGP configuration example Network requirements In Figure 57, run EBGP between Switch A and Switch B, and run IBGP between Switch B and Switch C so that Switch C can access the network 8.1.1.0/24 connected to Switch A.
[SwitchB-bgp] peer 3.3.3.3 connect-interface loopback 0 [SwitchB-bgp] ipv4-family unicast [SwitchB-bgp-ipv4] peer 3.3.3.3 enable [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit [SwitchB] ospf 1 [SwitchB-ospf-1] area 0 [SwitchB-ospf-1-area-0.0.0.0] network 2.2.2.2 0.0.0.0 [SwitchB-ospf-1-area-0.0.0.0] network 9.1.1.1 0.0.0.255 [SwitchB-ospf-1-area-0.0.0.0] quit [SwitchB-ospf-1] quit # Configure Switch C. system-view [SwitchC] bgp 65009 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 2.2.2.
[SwitchA-bgp] quit # Configure Switch B. [SwitchB] bgp 65009 [SwitchB-bgp] peer 3.1.1.2 as-number 65008 [SwitchB-bgp] ipv4-family unicast [SwitchB-bgp-ipv4] peer 3.1.1.2 enable [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit # Display BGP peer information on Switch B. [SwitchB] display bgp peer ipv4 BGP local router ID : 2.2.2.2 Local AS number : 65009 Total number of peers : 2 Peer Peers in established state : 2 AS MsgRcvd MsgSent OutQ PrefRcv Up/Down State 3.3.3.
>e 8.1.1.0/24 3.1.1.2 0 0 65008i # Display the BGP routing table on Switch C. [SwitchC] display bgp routing-table ipv4 Total number of routes: 1 BGP local router ID is 3.3.3.3 Status codes: * - valid, > - best, d - damped, h - history, s - suppressed, S - Stale, i - internal, e - external Origin: i - IGP, e - EGP, ? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn i 8.1.1.0/24 3.1.1.
Total number of routes: 4 BGP local router ID is 3.3.3.3 Status codes: * - valid, > - best, d - damped, h - history, s - suppressed, S - Stale, i - internal, e - external Origin: i - IGP, e - EGP, ? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn i 2.2.2.2/32 2.2.2.2 0 100 0 ? >i 3.1.1.0/24 2.2.2.2 0 100 0 ? >i 8.1.1.0/24 3.1.1.2 0 100 0 65008i >i 9.1.1.0/24 2.2.2.2 0 100 0 ? The output shows that the route 8.1.1.0 becomes valid with the next hop as Switch A.
Configuration considerations Configure BGP to redistribute routes from OSPF on Switch B, so Switch A can obtain the route to 9.1.2.0/24. Configure OSPF to redistribute routes from BGP on Switch B, so Switch C can obtain the route to 8.1.1.0/24. Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure OSPF: Enable OSPF in AS 65009, so Switch B can obtain the route to 9.1.2.0/24. # Configure Switch B.
4. Configure BGP and IGP route redistribution: # Configure route redistribution between BGP and OSPF on Switch B. [SwitchB-bgp-ipv4] import-route ospf 1 [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit [SwitchB] ospf 1 [SwitchB-ospf-1] import-route bgp [SwitchB-ospf-1] quit # Display the BGP routing table on Switch A. [SwitchA] display bgp routing-table ipv4 Total number of routes: 3 BGP local router ID is 1.1.1.
56 bytes from 9.1.2.1: icmp_seq=2 ttl=254 time=2.000 ms 56 bytes from 9.1.2.1: icmp_seq=3 ttl=254 time=7.000 ms 56 bytes from 9.1.2.1: icmp_seq=4 ttl=254 time=9.000 ms --- 9.1.2.1 ping statistics --5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss round-trip min/avg/max/stddev = 2.000/8.000/12.000/3.406 ms [SwitchC] ping -a 9.1.2.1 8.1.1.1 PING 8.1.1.1 (8.1.1.1) from 9.1.2.1: 56 data bytes 56 bytes from 8.1.1.1: icmp_seq=0 ttl=254 time=9.000 ms 56 bytes from 8.1.1.1: icmp_seq=1 ttl=254 time=4.
2. Configure static routing between Switch A and Switch B: # Configure a default route with the next hop 192.168.212.1 on Switch A. system-view [SwitchA] ip route-static 0.0.0.0 0 192.168.212.1 # Configure static routes to 192.168.64.0/24, 192.168.74.0/24, and 192.168.99.0/24 with the same next hop 192.168.212.161 on Switch B. system-view [SwitchB] ip route-static 192.168.64.0 24 192.168.212.161 [SwitchB] ip route-static 192.168.74.0 24 192.168.212.161 [SwitchB] ip route-static 192.
172.17.100.0/24 OSPF 10 1 172.17.100.2 Vlan100 The output shows that Switch C has learned routes to 192.168.64.0/24, 192.168.99.0/24, and 192.168.64.0/18 through OSPF. 4. Configure BGP between Switch C and Switch D and configure BGP on Switch C to redistribute OSPF routes: # On Switch C, enable BGP, specify Switch D as an EBGP peer, and configure BGP to redistribute OSPF routes. [SwitchC] bgp 65106 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 10.220.2.
[SwitchC-bgp-ipv4] quit [SwitchC-bgp] quit Verifying the configuration # Display IP routing table on Switch C. [SwitchC] display ip routing-table | include 192.168 192.168.64.0/18 BGP 130 0 127.0.0.1 NULL0 192.168.64.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.74.0/24 OSPF 150 1 172.17.100.1 Vlan100 192.168.99.0/24 OSPF 150 1 172.17.100.1 Vlan100 The output shows that Switch C has a summary route 192.168.64.0/18 with the output interface Null0.
Figure 60 Network diagram Configuration considerations On Switch A, establish EBGP connections with Switch B and Switch C. Configure BGP to advertise network 8.1.1.0/24 to Switch B and Switch C, so that Switch B and Switch C can access the internal network connected to Switch A. On Switch B, establish an EBGP connection with Switch A and an IBGP connection with Switch C. Configure BGP to advertise network 9.1.1.0/24 to Switch A, so that Switch A can access the intranet through Switch B.
[SwitchA-bgp] quit # Configure Switch B. system-view [SwitchB] bgp 65009 [SwitchB-bgp] router-id 2.2.2.2 [SwitchB-bgp] peer 3.1.1.2 as-number 65008 [SwitchB-bgp] peer 3.3.3.3 as-number 65009 [SwitchB-bgp] peer 3.3.3.3 connect-interface loopback 0 [SwitchB-bgp] ipv4-family unicast [SwitchB-bgp-ipv4] peer 3.1.1.2 enable [SwitchB-bgp-ipv4] peer 3.3.3.3 enable [SwitchB-bgp-ipv4] network 9.1.1.0 24 [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit [SwitchB] ip route-static 3.3.3.3 32 9.1.1.
is smaller). The route with next hop 3.1.2.1 is marked with an asterisk (*), indicating it is a valid route, but not the best. { By using the display ip routing-table command, you can find only one route to 9.1.1.0/24 with next hop 3.1.1.1 and outbound interface VLAN-interface 200. Configure loading balancing: 3. Because Switch A has two routes to reach AS 65009, configuring load balancing over the two BGP routes on Switch A can improve link usage. # Configure Switch A.
Figure 61 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure EBGP: # Configure Switch A. system-view [SwitchA] bgp 10 [SwitchA-bgp] router-id 1.1.1.1 [SwitchA-bgp] peer 200.1.2.2 as-number 20 [SwitchA-bgp] ipv4-family unicast [SwitchA-bgp-ipv4] peer 200.1.2.2 enable [SwitchA-bgp-ipv4] network 9.1.1.0 255.255.255.0 [SwitchA-bgp] quit # Configure Switch B. system-view [SwitchB] bgp 20 [SwitchB-bgp] router-id 2.2.2.
# Display the BGP routing table on Switch B. [SwitchB] display bgp routing-table ipv4 9.1.1.0 BGP local router ID: 2.2.2.2 Local AS number: 20 Paths: 1 available, 1 best BGP routing table information of 9.1.1.0/24: From : 200.1.2.1 (1.1.1.1) Relay nexthop : 200.1.2.1 Original nexthop: 200.1.2.1 OutLabel : NULL AS-path : 10 Origin : igp Attribute value : pref-val 0 State : valid, external, best, # Display advertisement information of network 9.1.1.0 on Switch B.
[SwitchA] route-policy comm_policy permit node 0 [SwitchA-route-policy-comm_policy-0] apply community no-export [SwitchA-route-policy-comm_policy-0] quit # Apply the routing policy. [SwitchA] bgp 10 [SwitchA-bgp] ipv4-family unicast [SwitchA-bgp-ipv4] peer 200.1.2.2 route-policy comm_policy export [SwitchA-bgp-ipv4] peer 200.1.2.2 advertise-community Verifying the configuration # Display the routing table on Switch B. [SwitchB] display bgp routing-table ipv4 9.1.1.0 BGP local router ID: 2.2.2.
BGP route reflector configuration example Network requirements In Figure 62, all switches run BGP. • Between Switch A and Switch B is an EBGP connection, between Switch C and Switch B, and between Switch C and Switch D are IBGP connections. • Switch C is a route reflector with clients Switch B and D. • Switch D can learn route 20.0.0.0/8 from Switch C. Figure 62 Network diagram Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2.
[SwitchB-bgp-ipv4] peer 192.1.1.1 enable [SwitchB-bgp-ipv4] peer 193.1.1.1 enable [SwitchB-bgp-ipv4] peer 193.1.1.1 next-hop-local [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit # Configure Switch C. system-view [SwitchC] bgp 200 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 193.1.1.2 as-number 200 [SwitchC-bgp] peer 194.1.1.2 as-number 200 [SwitchC-bgp] ipv4-family unicast [SwitchC-bgp-ipv4] peer 193.1.1.2 enable [SwitchC-bgp-ipv4] peer 194.1.1.
# Display the BGP routing table on Switch D. [SwitchD] display bgp routing-table ipv4 Total number of routes: 1 BGP local router ID is 4.4.4.4 Status codes: * - valid, > - best, d - damped, h - history, s - suppressed, S - Stale, i - internal, e - external Origin: i - IGP, e - EGP, ? - incomplete Network i 20.0.0.0 NextHop MED LocPrf PrefVal Path/Ogn 193.1.1.2 0 100 0 100i Switch D has learned route 20.0.0.0/8 from Switch C.
Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure BGP confederation: # Configure Switch A. system-view [SwitchA] bgp 65001 [SwitchA-bgp] router-id 1.1.1.1 [SwitchA-bgp] confederation id 200 [SwitchA-bgp] confederation peer-as 65002 65003 [SwitchA-bgp] peer 10.1.1.2 as-number 65002 [SwitchA-bgp] peer 10.1.2.2 as-number 65003 [SwitchA-bgp] ipv4-family unicast [SwitchA-bgp-ipv4] peer 10.1.1.2 enable [SwitchA-bgp-ipv4] peer 10.1.2.
[SwitchA-bgp] ipv4-family unicast [SwitchA-bgp-ipv4] peer 10.1.3.2 enable [SwitchA-bgp-ipv4] peer 10.1.4.2 enable [SwitchA-bgp-ipv4] peer 10.1.3.2 next-hop-local [SwitchA-bgp-ipv4] peer 10.1.4.2 next-hop-local [SwitchA-bgp-ipv4] quit [SwitchA-bgp] quit # Configure Switch D. system-view [SwitchD] bgp 65001 [SwitchD-bgp] router-id 4.4.4.4 [SwitchD-bgp] confederation id 200 [SwitchD-bgp] peer 10.1.3.1 as-number 65001 [SwitchD-bgp] peer 10.1.5.
[SwitchF-bgp-ipv4] network 9.1.1.0 255.255.255.0 [SwitchF-bgp-ipv4] quit [SwitchF-bgp] quit Verifying the configuration # Display the routing table on Switch B, which is similar to that on Switch C. [SwitchB] display bgp routing-table ipv4 Total number of routes: 1 BGP local router ID is 2.2.2.2 Status codes: * - valid, > - best, d - damped, h - history, s - suppressed, S - Stale, i - internal, e - external Origin: i - IGP, e - EGP, ? - incomplete Network NextHop MED LocPrf PrefVal Path/Ogn >i 9.1.
[SwitchD] display bgp routing-table ipv4 9.1.1.0 BGP local router ID: 4.4.4.4 Local AS number: 65001 Paths: 1 available, 1 best BGP routing table information of 9.1.1.0/24: From : 10.1.3.1 (1.1.1.1) Relay nexthop : 10.1.3.1 Original nexthop: 10.1.3.
Switch B Vlan-int100 192.1.1.1/24 Vlan-int200 193.1.1.1/24 Vlan-int100 192.1.1.2/24 Vlan-int300 194.1.1.2/24 Switch C Vlan-int300 194.1.1.1/24 Vlan-int400 195.1.1.2/24 Vlan-int200 193.1.1.2/24 Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure OSPF on Switch B, Switch C, and Switch D: # Configure Switch B. system-view [SwitchB] ospf [SwitchB-ospf] area 0 [SwitchB-ospf-1-area-0.0.0.0] network 192.1.1.0 0.0.0.
# Configure Switch B. [SwitchB] bgp 200 [SwitchB-bgp] peer 192.1.1.1 as-number 100 [SwitchB-bgp] peer 194.1.1.1 as-number 200 [SwitchB-bgp] ipv4-family unicast [SwitchB-bgp-ipv4] peer 192.1.1.1 enable [SwitchB-bgp-ipv4] peer 194.1.1.1 enable [SwitchB-bgp-ipv4] quit [SwitchB-bgp] quit # Configure Switch C. [SwitchC] bgp 200 [SwitchC-bgp] peer 193.1.1.1 as-number 100 [SwitchC-bgp] peer 195.1.1.1 as-number 200 [SwitchC-bgp] ipv4-family unicast [SwitchC-bgp-ipv4] peer 193.1.1.
# Apply routing policy apply_med_50 to the route advertised to peer 193.1.1.2 (Switch C), and apply_med_100 to the route advertised to peer 192.1.1.2 (Switch B). [SwitchA] bgp 100 [SwitchA-bgp] ipv4-family unicast [SwitchA-bgp-ipv4] peer 193.1.1.2 route-policy apply_med_50 export [SwitchA-bgp-ipv4] peer 192.1.1.2 route-policy apply_med_100 export [SwitchA-bgp-ipv4] quit [SwitchA-bgp] quit # Display the BGP routing table on Switch D.
BGP local router ID is 195.1.1.1 Status codes: * - valid, > - best, d - dampened, h - history, s - suppressed, S - stale, i - internal, e - external Origin: i - IGP, e - EGP, ? - incomplete Network >i 1.0.0.0 * i NextHop MED LocPrf PrefVal Path/Ogn 193.1.1.1 200 0 100i 192.1.1.1 100 0 100i Route 1.0.0.0/8 learned from Switch C is the optimal. BGP GR configuration example Network requirements In Figure 65 are all BGP switches. EBGP runs between Switch A and Switch B.
# Configure IP addresses for interfaces. (Details not shown.) # Configure the EBGP connection. system-view [SwitchB] bgp 65009 [SwitchB-bgp] router-id 2.2.2.2 [SwitchB-bgp] peer 200.1.1.2 as-number 65008 # Configure the IBGP connection. [SwitchB-bgp] peer 9.1.1.2 as-number 65009 # Enable GR capability for BGP. [SwitchB-bgp] graceful-restart # Inject networks 200.1.1.0/24 and 9.1.1.0/24 to the BGP routing table. [SwitchB-bgp] ipv4-family [SwitchB-bgp-ipv4] network 200.1.1.
Figure 66 Network diagram Device Interface IP address Device Interface IP address Switch A Vlan-int100 3.0.1.1/24 Switch C Vlan-int101 3.0.2.2/24 Vlan-int200 2.0.1.1/24 Vlan-int201 2.0.2.2/24 Vlan-int100 3.0.1.2/24 Vlan-int200 2.0.1.2/24 Vlan-int101 3.0.2.1/24 Vlan-int201 2.0.2.1/24 Switch B Switch D Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure OSPF to make sure that Switch A and Switch C are reachable to each other.
[SwitchA-route-policy-apply_med_50-10] if-match ip address acl 2000 [SwitchA-route-policy-apply_med_50-10] apply cost 50 [SwitchA-route-policy-apply_med_50-10] quit [SwitchA] route-policy apply_med_100 permit node 10 [SwitchA-route-policy-apply_med_100-10] if-match ip address acl 2000 [SwitchA-route-policy-apply_med_100-10] apply cost 100 [SwitchA-route-policy-apply_med_100-10] quit # Apply routing policy apply_med_50 to routes outgoing to peer 3.0.2.
Rx Count: 135 Tx Count: 135 Connect Type: Indirect Running Up for: 00:00:58 Hold Time: 2457ms Auth mode: None Detect Mode: Async Slot: 0 Protocol: BGP Diag Info: No Diagnostic The output shows that a BFD session has been established between Switch A and Switch C and that BFD runs correctly. # Display BGP peer information on Switch C. display bgp peer ipv4 BGP local router ID: 3.3.3.
When the path Switch C<—>Switch B<—>Switch A fails, Switch C can quickly detect the link failure and notify BGP to change the relevant IBGP session state. # Display route 1.1.1.0/24 on Switch C. display ip routing-table 1.1.1.0 24 verbose Summary Count : 1 Destination: 1.1.1.
2. Configure IBGP: # Configure Switch B. system-view [SwitchB] bgp 65009 [SwitchB-bgp] router-id 2.2.2.2 [SwitchB-bgp] peer 9::2 as-number 65009 [SwitchB-bgp] ipv6-family [SwitchB-bgp-ipv6] peer 9::2 enable [SwitchB-bgp-ipv6] quit # Configure Switch C. system-view [SwitchC] bgp 65009 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 9::1 as-number 65009 [SwitchC-bgp] ipv6-family [SwitchC-bgp-ipv6] peer 9::1 enable 3. Configure EBGP: # Configure Switch A.
Verifying the configuration # Display IPv6 BGP peer information on Switch B. [SwitchB] display bgp peer ipv6 BGP local router ID: 2.2.2.
Path/Ogn: i The output shows that Switch A has learned routing information of AS 65009. # Display IPv6 BGP routing table information on Switch C. [SwitchC] display bgp routing-table ipv6 Total number of routes: 4 BGP local router ID is 3.3.3.
Figure 68 Network diagram Configuration procedure 1. Configure IPv6 addresses for interfaces and IPv4 addresses for loopback interfaces. (Details not shown.) 2. Configure IBGP and EBGP connections and advertise network routes through IPv6 BGP: # Configure Switch A. system-view [SwitchA] bgp 100 [SwitchA-bgp] router-id 1.1.1.
[SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 101::2 as-number 200 [SwitchC-bgp] peer 102::2 as-number 200 [SwitchC-bgp] ipv6-family [SwitchC-bgp-ipv6] peer 101::2 enable [SwitchC-bgp-ipv6] peer 102::2 enable [SwitchC-bgp-ipv6] network 101:: 96 [SwitchC-bgp-ipv6] network 102:: 96 # Configure Switch D. system-view [SwitchD] bgp 200 [SwitchD-bgp] router-id 4.4.4.
MED : 0 Path/Ogn: i > Network : 102:: PrefixLen : 96 NextHop : :: LocPrf : PrefVal : 32768 OutLabel : NULL MED : 0 Path/Ogn: i * i Network : 102:: PrefixLen : 96 NextHop : 102::1 LocPrf : 100 PrefVal : 0 OutLabel : NULL MED : 0 Path/Ogn: i The output shows that Switch D has learned the network 1::/64 from Switch C through route reflection. BFD for IPv6 BGP configuration example Network requirements As shown in Figure 69, configure OSPFv3 as the IGP in AS 200.
Switch B Vlan-int100 3000::2/64 Vlan-int101 3001::2/64 Switch D Vlan-int200 2000::2/64 Vlan-int201 2001::2/64 Configuration procedure 1. Configure IPv6 addresses for interfaces. (Details not shown.) 2. Configure OSPFv3 so that Switch A and Switch C can reach each other. (Details not shown.) 3. Configure IPv6 BGP on Switch A: # Establish two IBGP connections to Switch C. system-view [SwitchA] bgp 200 [SwitchA-bgp] router-id 1.1.1.
[SwitchC] bgp 200 [SwitchC-bgp] router-id 3.3.3.3 [SwitchC-bgp] peer 3000::1 as-number 200 [SwitchC-bgp] peer 2000::1 as-number 200 [SwitchC-bgp] ipv6-family [SwitchC-bgp-ipv6] peer 3000::1 enable [SwitchC-bgp-ipv6] peer 2000::1 enable [SwitchC-bgp-ipv6] quit # Enable BFD for peer 3001::1. [SwitchC-bgp] peer 3000::1 bfd [SwitchC-bgp] quit [SwitchC] quit Verifying the configuration # Display detailed BFD session information on Switch C.
The output shows that Switch C has established two BGP connections with Switch A, and both connections are in Established state. # Display route 1200::0/64 on Switch C.
Destination: 1200::/64 Protocol: BGP4+ Process ID: 0 SubProtID: 0x1 Age: 00h00m57s Cost: 100 Preference: 255 Tag: 0 State: Active Adv OrigTblID: 0x1 OrigVrf: default-vrf TableID: 0xa OrigAs: 0 NBRID: 0x25000000 LastAs: 0 AttrID: 0x0 Neighbor: 2000::1 Flags: 0x10060 OrigNextHop: 2000::1 Label: NULL RealNextHop: FE80::20C:29FF:FE40:715 BkLabel: NULL BkNextHop: N/A Tunnel ID: Invalid BkTunnel ID: Invalid Interface: Vlan-interface201 BkInterface: N/A The output shows that Switch C commun
8. Verify that no ACL rule is applied to disable TCP port 179.
Configuring PBR Introduction to PBR Different from destination-based routing, policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop and other parameters for packets that match specific criteria, such as ACLs. A device uses PBR to forward matching packets and uses the routing table to forward other packets. If PBR is not configured, the device uses the routing table to forward packets.
Does a packet match all the if-match clauses on the node? Match mode permit Deny • If the node is configured with an apply clause, PBR executes the apply clause on the node. Yes. • If the node is configured with no The packet is forwarded according to the routing table. PBR matches the packet against the next node. PBR matches the packet against the next node. apply clause, the packet is forwarded according to the routing table. No. A node that has no if-match clauses matches any packet.
Step 2. Create a node for a policy, and enter policy node view. Command Remarks policy-based-route policy-name [ deny | permit ] node node-number By default, no policy node is created. Configuring match criteria for a node Step Command Remarks 1. Enter system view. system-view N/A 2. Enter policy node view. policy-based-route policy-name [ deny | permit ] node node-number N/A 3. Configure an ACL match criterion. if-match acl acl-number By default, no ACL match criterion is configured.
To configure interface PBR: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Apply a policy to the interface. ip policy-based-route policy-name By default, no policy is applied to the interface. Displaying and maintaining PBR Execute display commands in any view and reset commands in user view. Task Command Display PBR policy information.
Figure 70 Network diagram Configuration procedure 1. Configure Switch A: # Configure ACL 3101 to match TCP packets. system-view [SwitchA] acl number 3101 [SwitchA-acl-adv-3101] rule permit tcp [SwitchA-acl-adv-3101] quit # Configure Node 5 for policy aaa to forward TCP packets to next hop 1.1.2.2. [SwitchA] policy-based-route aaa permit node 5 [SwitchA-pbr-aaa-5] if-match acl 3101 [SwitchA-pbr-aaa-5] apply next-hop 1.1.2.
2. Configure Switch B: # Configure a static route to subnet 10.110.0.0/24. system-view [SwitchB] ip route-static 10.110.0.0 24 1.1.2.1 # Configure the IP address of VLAN-interface 10. [SwitchB] interface vlan-interface 10 [SwitchB-Vlan-interface10] ip address 1.1.2.2 255.255.255.0 3. Configure Switch C: # Configure a static route to subnet 10.110.0.0/24. system-view [SwitchC] ip route-static 10.110.0.0 24 1.1.3.1 # Configure the IP address of VLAN-interface 20.
Configuring IPv6 static routing Static routes are manually configured and cannot adapt to network topology changes. If a fault or a topological change occurs in the network, the network administrator must modify the static routes manually. IPv6 static routing works well in a simple IPv6 network. Configuring an IPv6 static route Before you configure an IPv6 static route, complete the following tasks: • Configure parameters for the related interfaces.
IMPORTANT: Enabling BFD for a flapping route could worsen the situation. BFD provides a general purpose, standard, and medium- and protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of the bidirectional forwarding paths between two routers for protocols, such as routing protocols and MPLS. For more information about BFD, see High Availability Configuration Guide.
Single-hop echo mode With BFD echo mode enabled for a static route, the output interface sends BFD echo packets to the destination device, which loops the packets back to test the link reachability. IMPORTANT: Do not use BFD for a static route with the output interface in spoofing state. To configure BFD echo mode for an IPv6 static route: Step 1. Enter system view. Command Remarks system-view N/A By default, the source address of echo packets is not configured. 2.
IPv6 static routing configuration examples Basic IPv6 static route configuration example Network requirements As shown in Figure 71, configure IPv6 static routes so that hosts can reach one another. Figure 71 Network diagram Host B 2::2/64 Vlan-int400 2::1/64 Vlan-int200 4::2/64 Vlan-int300 5::2/64 Switch B Vlan-int200 4::1/64 Vlan-int300 5::1/64 Vlan-int100 1::1/64 Host A 1::2/64 Vlan-int500 3::1/64 Switch C Switch A Host C 3::2/64 Configuration procedure 1.
Static Routing table Status : Summary Count : 1 Destination: :: Protocol : Static NextHop : 4::2 Preference: 60 Interface : Vlan-interface200 Cost : 0 Destination: 1::/64 Protocol : Static NextHop : 4::1 Preference: 60 Interface : Vlan-interface200 Cost : 0 Destination: 3::/64 Protocol : Static NextHop : 5::1 Preference: 60 Interface : Vlan-interface300 Cost Static Routing table Status : Summary Count : 0 # Display the IPv6 static route information on Switch
BFD for IPv6 static routes configuration example (direct next hop) Network requirements In Figure 72, configure an IPv6 static route to subnet 120::/64 on Switch A, and configure an IPv6 static route to subnet 121::/64 on Switch B. Enable BFD for both routes. Configure an IPv6 static route to subnet 120::/64 and an IPv6 static route to subnet 121::/64 on Switch C.
system-view [SwitchB] interface vlan-interface 10 [SwitchB-vlan-interface10] bfd min-transmit-interval 500 [SwitchB-vlan-interface10] bfd min-receive-interval 500 [SwitchB-vlan-interface10] bfd detect-multiplier 9 [SwitchB-vlan-interface10] quit [SwitchB] ipv6 route-static 121:: 64 vlan-interface 10 FE80::2A0:FCFF:FE00:580A bfd control-packet [SwitchB] ipv6 route-static 121:: 64 vlan-interface 13 13::2 preference 65 [SwitchB] quit # Configure IPv6 static routes on Switch C.
# Display IPv6 static routes on Switch A again. display ipv6 routing-table protocol static Summary Count : 1 Static Routing table Status : Summary Count : 1 Destination: 120::/64 Protocol : Static NextHop : 10::100 Preference: 65 Interface : Vlan11 Cost : 0 Static Routing table Status : < Inactive> Summary Count : 0 The output shows that Switch A communicates with Switch B through VLAN-interface 11.
Switch A Switch C Vlan-int10 12::1/64 Vlan-int11 10::102/64 Loop1 1::9/128 Vlan-int11 10::100/64 Vlan-int13 13::2/64 Switch B Switch D Vlan-int12 11::2/64 Vlan-int13 13::1/64 Loop1 2::9/128 Vlan-int10 12::2/64 Vlan-int12 11::1/64 Configuration procedure 1. Configure IPv6 addresses for interfaces. (Details not shown.) 2.
IPv6 Session Working Under Ctrl Mode: Local Discr: 513 Remote Discr: 33 Source IP: FE80::1:1B49 (link-local address of Loopback1 on Switch A) Destination IP: FE80::1:1B49 (link-local address of Loopback1 on Switch B) Session State: Up Interface: Loop1 Hold Time: 2012ms The output shows that the BFD session has been created. # Display the IPv6 static routes on Switch A.
Configuring an IPv6 default route A default IPv6 route is used to forward packets that match no entry in the routing table. A default IPv6 route can be configured in either of the following ways: • The network administrator can configure a default route with a destination prefix of ::/0. For more information, see "Configuring an IPv6 static route." • Some dynamic routing protocols, such as OSPFv3, IPv6 IS-IS, and RIPng, can generate a default IPv6 route.
Configuring RIPng RIP next generation (RIPng) is an extension of RIP-2 for support of IPv6. Most RIP concepts are applicable to RIPng. Overview RIPng is a distance vector routing protocol. It employs UDP to exchange route information through port 521. RIPng uses a hop count to measure the distance to a destination. The hop count is the metric or cost. The hop count from a router to a directly connected network is 0. The hop count between two directly connected routers is 1.
RIPng packets RIPng uses request and response packets to exchange routing information as follows: 1. When RIPng starts or needs to update some routing entries, it sends a multicast request packet to neighbors. 2. When a RIPng neighbor receives the request packet, it sends back a response packet that contains the local routing table. RIPng can also advertise route updates in response packets periodically or advertise a triggered update caused by a route change. 3.
Step Command Remarks 1. Enter system view. system-view N/A 2. Create a RIPng process and enter its view. ripng [ process-id ] [ vpn-instance vpn-instance-name ] By default, the RIPng process is not created. 3. Return to system view. quit N/A 4. Enter interface view. interface interface-type interface-number N/A By default, RIPng is disabled. Enable RIPng on the interface. 5.
RIPng route summarization improves network scalability, reduces routing table size, and increases routing table lookup efficiency. RIPng advertises a summary route with the smallest metric of all the specific routes. For example, RIPng has two specific routes to be advertised through an interface: 1:11:11::24 with a metric of a 2 and 1:11:12::34 with a metric of 3. Configure route summarization on the interface, so RIPng advertises a single route 11::0/16 with a metric of 2.
Step Command Remarks 3. Configure a filter policy to filter received routes. filter-policy { acl6-number | prefix-list prefix-list-name } import By default, RIPng does not filter received routing information. 4. Configure a filter policy to filter redistributed routes. filter-policy { acl6-number | prefix-list prefix-list-name } export [ protocol [ process-id ] ] By default, RIPng does not filter redistributed routing information.
Configuring RIPng timers You can adjust RIPng timers to optimize the performance of the RIPng network. When you adjust RIPng timers, consider the network performance, and perform unified configurations on routers running RIPng to avoid unnecessary network traffic or route oscillation. To configure RIPng timers: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter RIPng view. ripng [ process-id ] [ vpn-instance vpn-instance-name ] N/A Configure RIPng timers.
Step Command Remarks 2. Enter interface view. interface interface-type interface-number N/A 3. Enable poison reverse. ripng poison-reverse By default, poison reverse is disabled. Configuring zero field check on RIPng packets Some fields in the RIPng packet header must be zero. These fields are called "zero fields." You can enable zero field check on incoming RIPng packets. If a zero field of a packet contains a non-zero value, RIPng does not process the packets.
GR Helper—A neighbor of the GR Restarter. It helps the GR Restarter to complete the GR process. • After RIPng restarts on a router, the router must learn RIPng routes again and updates its FIB table, which causes network disconnections and route reconvergence. With the GR feature, the restarting router (known as the "GR Restarter") can notify the event to its GR capable neighbors. GR capable neighbors (known as "GR Helpers") keep their adjacencies with the router within a configurable GR interval.
Figure 74 Network diagram Configuration procedure 1. Configure IPv6 addresses for interfaces. (Details not shown.) 2. Configure basic RIPng: # Configure Switch A. system-view [SwitchA] ripng 1 [SwitchA-ripng-1] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] ripng 1 enable [SwitchA-Vlan-interface100] quit [SwitchA] interface vlan-interface 400 [SwitchA-Vlan-interface400] ripng 1 enable [SwitchA-Vlan-interface400] quit # Configure Switch B.
[SwitchB] display ripng 1 route Route Flags: A - Aging, S - Suppressed, G - Garbage-collect ---------------------------------------------------------------- Peer FE80::20F:E2FF:FE23:82F5 on Vlan-interface100 Dest 1::/64, via FE80::20F:E2FF:FE23:82F5, cost 1, tag 0, A, 6 Sec Dest 2::/64, via FE80::20F:E2FF:FE23:82F5, cost Peer FE80::20F:E2FF:FE00:100 1, tag 0, A, 6 Sec on Vlan-interface200 Dest 3::/64, via FE80::20F:E2FF:FE00:100, cost 1, tag 0, A, 11 Sec Dest 4::/64, via FE80::20F:E2FF:FE00:100,
via FE80::2:100, cost 1, tag 0, A, 6 secs Peer FE80::3:200 on Vlan-interface200 Destination 3::/64, via FE80::2:200, cost 1, tag 0, A, 11 secs Destination 4::/64, via FE80::2:200, cost 1, tag 0, A, 11 secs Destination 5::/64, via FE80::2:200, cost 1, tag 0, A, 11 secs [SwitchA] display ripng 1 route Route Flags: A - Aging, S - Suppressed, G - Garbage-collect ---------------------------------------------------------------- Peer FE80::2:100 on Vlan-interface100 Destination 4::/64, via FE80::1:100, cost 2,
[SwitchA-Vlan-interface200] ripng 100 enable [SwitchA-Vlan-interface200] quit # Enable RIP 100 and RIP 200 on Switch B. system-view [SwitchB] ripng 100 [SwitchB-ripng-100] quit [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] ripng 100 enable [SwitchB-Vlan-interface100] quit [SwitchB] ripng 200 [SwitchB-ripng-200] quit [SwitchB] interface vlan-interface 300 [SwitchB-Vlan-interface300] ripng 200 enable [SwitchB-Vlan-interface300] quit # Enable RIPng 200 on Switch C.
3. Destination: FE80::/10 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Cost : 0 Destination: FF00::/8 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Cost : 0 Configure RIPng route redistribution: # Configure route redistribution between the two RIPng processes on Switch B.
Interface : NULL0 Cost : 0d Destination: FF00::/8 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Cost 307 : 0
Configuring OSPFv3 This chapter describes how to configure RFC 2740-compliant Open Shortest Path First version 3 (OSPFv3) for an IPv6 network. For more information about OSPFv2, see "Configuring OSPF.
• Router-LSA—Originated by all routers. This LSA describes the collected states of the router's interfaces to an area, and is flooded throughout a single area only. • Network-LSA—Originated for broadcast and NBMA networks by the DR. This LSA contains the list of routers connected to the network, and is flooded throughout a single area only. • Inter-Area-Prefix-LSA—Originated by ABRs and flooded throughout the LSA's associated area.
Tasks at a glance (Optional.) Configuring OSPFv3 route control: • • • • • • • Configuring OSPFv3 route summarization Configuring OSPFv3 received route filtering Configuring Inter-Area-Prefix LSA filtering Configuring an OSPFv3 cost for an interface Configuring the maximum number of OSPFv3 ECMP routes Configuring a preference for OSPFv3 Configuring OSPFv3 route redistribution (Optional.
Step Command Remarks 3. Specify a router ID. router-id router-id By default, no router ID is configured. 4. Enter interface view. interface interface-type interface-number N/A 5. Enable an OSPFv3 process on the interface. ospfv3 process-id area area-id [ instance instance-id ] No OSPFv3 process is enabled on an interface by default. Configuring OSPFv3 area parameters OSPFv3 has the same stub area and virtual link features as OSPFv2.
Step (Optional.) Specify a cost for the default route advertised to the stub area. 5. Command Remarks default-cost value The default setting is 1. Configuring an OSPFv3 virtual link You can configure a virtual link to maintain connectivity between a non-backbone area and the backbone, or in the backbone itself. IMPORTANT: • Both ends of a virtual link are ABRs that must be configured with the vlink-peer command. • Do not configure virtual links in the areas of a GR-capable process.
Configuration prerequisites Before you configure OSPFv3 network types, enable OSPFv3. Configuring the OSPFv3 network type for an interface Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Configure a network type for the OSPFv3 interface.
Configuring OSPFv3 route summarization If contiguous network segments exist in an area, you can use the abr-summary command to summarize them into one network segment on the ABR. The ABR will advertise only the summary route. Any LSA falling into the specified network segment will not be advertised, reducing the LSDB size in other areas. To configure route summarization: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPFv3 view.
Step Command Configure OSPFv3 to filter Inter-Area-Prefix-LSAs. 3. Remarks filter { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } { export | import } By default, OSPFv3 accepts all Inter-Area-Prefix-LSAs. This command takes effect only on ABRs. Configuring an OSPFv3 cost for an interface You can configure an OSPFv3 cost for an interface with one of the following methods: • Configure the cost value in interface view.
Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] * N/A maximum load-balancing maximum By default, the maximum number of ECMP routes is the same as that configured in the max-ecmp-num command. For more information about the max-ecmp-num command, see IP Routing Command Reference. 3. Specify the maximum number of ECMP routes. Configuring a preference for OSPFv3 A router can run multiple routing protocols.
Step Command Remarks By default, route redistribution is disabled. 4. Configure OSPFv3 to redistribute routes from other routing protocols. import-route protocol [ process-id | all-processes | allow-ibgp ] [ cost cost | route-policy route-policy-name | type type ] * 5. (Optional.) Configure OSPFv3 to redistribute a default route. default-route-advertise [ [ always | permit-calculate-other ] | cost cost | route-policy route-policy-name | type type ] * By default, no default route is redistributed.
Step Command Remarks By default, the poll interval is 120 seconds. 5. Configure the poll interval. ospfv3 timer poll seconds [ instance instance-id ] 6. Configure the LSA retransmission interval. ospfv3 timer retransmit interval [ instance instance-id ] The default setting is 5 seconds. The LSA retransmission interval cannot be too short. Otherwise, unnecessary retransmissions will occur.
Step Command Remarks By default: • The maximum interval is 5 3. Specify the SPF calculation interval. seconds. spf-schedule-interval maximum-interval [ minimum-interval [ incremental-interval ] ] • The minimum interval is 50 milliseconds. • The incremental interval is 200 milliseconds. Specifying the LSA generation interval You can adjust the LSA generation interval to protect network resources and routers from being over consumed by frequent network changes.
Ignoring MTU check for DD packets When LSAs are few in DD packets, it is unnecessary to check the MTU in DD packets to improve efficiency. To ignore MTU check for DD packets: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Ignore MTU check for DD packets. ospfv3 mtu-ignore [ instance instance-id ] By default, OSPFv3 does not ignore MTU check for DD packets.
Step Command Remarks 2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] * N/A 3. Enable the logging of neighbor state changes. log-peer-change By default, this feature is enabled. Configuring OSPFv3 GR GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs. Two routers are required to complete a GR process. The following are router roles in a GR process. • GR Restarter—Graceful restarting router. It must be GR capable.
To configure GR Helper Step Command Remarks 1. Enter system view. system-view N/A 2. Enter OSPFv3 view. ospfv3 [ process-id | vpn-instance vpn-instance-name ] * N/A 3. Enable the GR Helper capability. graceful-restart helper enable By default, the GR Helper capability is enabled. 4. Enable strict LSA checking. graceful-restart helper strict-lsa-checking By default, strict LSA checking is disabled.
Purpose Command Display information about the routes to OSPFv3 ABR and ASBR. display ospfv3 [ process-id ] abr-asbr Display brief OSPFv3 process information. display ospfv3 [ process-id ] brief Display GR status of the specified OSPFv3 process. display ospfv3 [ process-id ] graceful-restart status Display OSPFv3 interface information. display ospfv3 [ process-id ] interface [ interface-type interface-number | verbose ] Display OSPFv3 LSDB information.
Figure 76 Network diagram Configuration procedure 1. Configure IPv6 addresses for interfaces. (Details not shown.) 2. Configure basic OSPFv3: # Configure Switch A: enable OSPFv3 and specify the router ID as 1.1.1.1. system-view [SwitchA] ospfv3 [SwitchA-ospfv3-1] router-id 1.1.1.
[SwitchC-Vlan-interface100] quit [SwitchC] interface vlan-interface 400 [SwitchC-Vlan-interface400] ospfv3 1 area 2 [SwitchC-Vlan-interface400] quit # Configure Switch D: enable OSPFv3 and specify the router ID as 4.4.4.4. system-view [SwitchD] ospfv3 [SwitchD-ospfv3-1] router-id 4.4.4.4 [SwitchD-ospfv3-1] quit [SwitchD] interface vlan-interface 400 [SwitchD-Vlan-interface400] ospfv3 1 area 2 [SwitchD-Vlan-interface400] quit # Display OSPFv3 neighbors on Switch B.
*Destination: 2001::/64 Type : IA Cost NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400 : 2 *Destination: 2001:1::/64 Type : IA Cost NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400 : 3 *Destination: 2001:2::/64 Type : I Cost NextHop : directly-connected Interface: Vlan400 : 1 *Destination: 2001:3::/64 Type : IA Cost NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400 : 4 Total: 4 Intra area: 1 3.
NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400 *Destination: 2001:2::/64 Type : I Cost : 1 NextHop : directly-connected Interface: Vlan400 *Destination: 2001:3::/64 Type : IA Cost : 4 NextHop : FE80::F40D:0:93D0:1 Interface: Vlan400 Total: 5 Intra area: 1 Inter area: 4 ASE: 0 The output shows that a default route is added, and its cost is the cost of a direct route plus the configured cost. 4.
• Configure router priority 2 for Switch C, the second highest priority on the network, so it will become the BDR. • Configure router priority 0 for Switch B, so it cannot become a DR or BDR. • Switch D uses the default router priority 1. Figure 77 Network diagram Configuration procedure 1. Configure IPv6 addresses for interfaces. (Details not shown.) 2. Configure basic OSPFv3: # Configure Switch A: enable OSPFv3 and specify the router ID as 1.1.1.1.
[SwitchC-Vlan-interface100] quit # Configure Switch D: enable OSPFv3 and specify the router ID as 4.4.4.4. system-view [SwitchD] ospfv3 [SwitchD-ospfv3-1] router-id 4.4.4.4 [SwitchD-ospfv3-1] quit [SwitchD] interface vlan-interface 200 [SwitchD-Vlan-interface200] ospfv3 1 area 0 [SwitchD-Vlan-interface200] quit # Display neighbor information on Switch A.
# Display neighbor information on Switch A. Router priorities have been updated, but the DR and BDR are not changed. [SwitchA] display ospfv3 peer OSPFv3 Process 1 with Router ID 1.1.1.1 Area: 0.0.0.0 ------------------------------------------------------------------------Router ID Pri State Dead-Time Interface Inst ID 2.2.2.2 0 2-Way/DROther 00:00:36 Vlan200 0 3.3.3.3 2 Full/Backup 00:00:35 Vlan200 0 4.4.4.4 1 Full/DR 00:00:33 Vlan200 0 # Display neighbor information on Switch D.
2.2.2.2 0 2-Way/DROther 00:00:37 Vlan200 0 3.3.3.3 2 Full/Backup 00:00:31 Vlan100 0 The output shows that Switch A becomes the DR. Configuring OSPFv3 route redistribution Network requirements As shown in Figure 78: • Switch A, Switch B, and Switch C are in Area 2. • OSPFv3 process 1 and OSPFv3 process 2 run on Switch B. Switch B communicates with Switch A and Switch C through OSPFv3 process 1 and OSPFv3 process 2.
[SwitchB] ospfv3 1 [SwitchB-ospfv3-1] router-id 2.2.2.2 [SwitchB-ospfv3-1] quit [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] ospfv3 1 area 2 [SwitchB-Vlan-interface100] quit [SwitchB] ospfv3 2 [SwitchB-ospfv3-2] router-id 3.3.3.3 [SwitchB-ospfv3-2] quit [SwitchB] interface vlan-interface 300 [SwitchB-Vlan-interface300] ospfv3 2 area 2 [SwitchB-Vlan-interface300] quit # Enable OSPFv3 process 2 on Switch C. system-view [SwitchC] ospfv3 2 [SwitchC-ospfv3-2] router-id 4.4.4.
3. Destination: FE80::/10 Protocol NextHop : :: Preference: 0 : Direct Interface : NULL0 Cost : 0 Destination: FF00::/8 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Configure OSPFv3 route redistribution: # Configure OSPFv3 process 2 to redistribute direct routes and the routes from OSPFv3 process 1 on Switch B.
Destination: FE80::/10 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Cost : 0 Destination: FF00::/8 Protocol : Direct NextHop : :: Preference: 0 Interface : NULL0 Configuring OSPFv3 GR Network requirements • As shown in Figure 79, Switch A, Switch B, and Switch C that reside in the same AS and the same OSPFv3 routing domain are GR capable. • Switch A acts as the GR Restarter.
[SwitchB] ospfv3 1 [SwitchB-ospfv3-1] router-id 2.2.2.2 [SwitchB-ospfv3-1] quit [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] ospfv3 1 area 1 [SwitchB-Vlan-interface100] quit # On Switch C, enable OSPFv3 and set the router ID to 3.3.3.3. (By default, GR helper is enabled on Switch C.) system-view [SwitchC] ospfv3 1 [SwitchC-ospfv3-1] router-id 3.3.3.
Switch C Vlan-int11 2001:2::2/64 Vlan-int13 2001:3::1/64 Configuration procedure 1. Configure IP addresses for the interfaces. (Details not shown.) 2. Configure basic OSPF: # On Switch A, enable OSPFv3 and specify the router ID as 1.1.1.1. system-view [SwitchA] ospfv3 [SwitchA-ospfv3-1] router-id 1.1.1.
[SwitchA-Vlan-interface10] bfd min-receive-interval 500 [SwitchA-Vlan-interface10] bfd detect-multiplier 7 [SwitchA-Vlan-interface10] return # Enable BFD and configure BFD parameters on Switch B.
Configuring IPv6 IS-IS IPv6 IS-IS supports all IPv4 IS-IS features except that it advertises IPv6 routing information. This chapter describes only IPv6 IS-IS specific configuration tasks. For information about IS-IS, see "Configuring IS-IS." Overview Intermediate System-to-Intermediate System (IS-IS) supports multiple network protocols, including IPv6. To support IPv6, the IETF added two type-length-values (TLVs) and a new network layer protocol identifier (NLPID).
Step Command Remarks 6. Enter interface view. interface interface-type interface-number N/A 7. Enable IPv6 for an IS-IS process on the interface. isis ipv6 enable [ process-id ] The default setting is disabled. Configuring IPv6 IS-IS route control Before you configure IPv6 IS-IS route control, complete basic IPv6 IS-IS configuration. To configure IPv6 IS-IS route control: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IS-IS view.
Step Command Remarks 11. Configure route advertisement from Level-1 to Level-2. ipv6 import-route isisv6 level-1 into level-2 [ filter-policy { acl6-number | prefix-list prefix-list-name | route-policy route-policy-name } | tag tag ] * By default, IPv6 IS-IS advertises routes from Level-1 to Level-2. ipv6 maximum load-balancing number By default, the maximum number of ECMP routes is the same as that configured in the max-ecmp-num command.
Task Command Display information about routes redistributed by IPv6 IS-IS. display isis redistribute ipv6 [ ipv6-address mask-length ] [ level-1 | level-2 ] [ process-id ] Display IPv6 IS-IS routing information.
# Configure Switch B. system-view [SwitchB] isis 1 [SwitchB-isis-1] is-level level-1 [SwitchB-isis-1] network-entity 10.0000.0000.0002.00 [SwitchB-isis-1] ipv6 enable [SwitchB-isis-1] quit [SwitchB] interface vlan-interface 200 [SwitchB-Vlan-interface200] isis ipv6 enable 1 [SwitchB-Vlan-interface200] quit # Configure Switch C. system-view [SwitchC] isis 1 [SwitchC-isis-1] network-entity 10.0000.0000.0003.
----------------------------- Destination : :: PrefixLen: 0 Flag : R/-/- Cost Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100 : 10 Destination : 2001:1:: PrefixLen: 64 Flag : D/L/- Cost Next Hop : Direct Interface: Vlan100 : 10 Destination : 2001:2:: PrefixLen: 64 Flag : R/-/- Cost Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100 : 20 Destination : 2001:3:: PrefixLen: 64 Flag : R/-/- Cost Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan100 : 20 Flags: D-Direct, R-Added
Route information for IS-IS(1) ------------------------------ Level-1 IPv6 Forwarding Table ----------------------------- Destination : 2001:1:: PrefixLen: 64 Flag : D/L/- Cost Next Hop : Direct Interface: Vlan100 : 10 Destination : 2001:2:: PrefixLen: 64 Flag : D/L/- Cost Next Hop : Direct Interface: Vlan200 : 10 Destination : 2001:3:: PrefixLen: 64 Flag : D/L/- Cost Next Hop : Direct Interface: Vlan300 : 10 Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit S
----------------------------- Destination : 2001:1:: PrefixLen: 64 Flag : R/-/- Cost Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan300 : 20 Destination : 2001:2:: PrefixLen: 64 Flag : R/-/- Cost Next Hop : FE80::200:FF:FE0F:4 Interface: Vlan300 : 20 Destination : 2001:3:: PrefixLen: 64 Flag : D/L/- Cost Next Hop : Direct Interface: Vlan300 : 10 Destination : 2001:4::1 PrefixLen: 128 Flag : D/L/- Cost Next Hop : Direct Interface: Loop1 : 0 Flags: D-Direct, R-Added to Rib,
Configuration procedure 1. Configure IP addresses for interfaces. (Details not shown.) 2. Configure IPv6 IS-IS: # Configure Switch A. system-view [SwitchA] isis 1 [SwitchA-isis-1] is-level level-1 [SwitchA-isis-1] network-entity 10.0000.0000.0001.
[SwitchA-Vlan-interface10] isis ipv6 bfd enable [SwitchA-Vlan-interface10] bfd min-transmit-interval 500 [SwitchA-Vlan-interface10] bfd min-receive-interval 500 [SwitchA-Vlan-interface10] bfd detect-multiplier 7 [SwitchA-Vlan-interface10] return # Enable BFD and configure BFD parameters on Switch B.
The output shows that Switch A and Switch B communicate through VLAN-interface 11.
Configuring IPv6 PBR Introduction to IPv6 PBR Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop and other parameters for packets that match specific criteria such as ACLs. A device uses PBR to forward matching packets and uses the routing table to forward non-matching packets. If PBR is not configured, the device uses the routing table to forward packets.
Does a packet match all the if-match clauses on the node? Match mode In permit mode In deny mode • If the node is configured with an apply clause, IPv6 PBR executes the apply clause on the node. Yes • If the node is configured with no apply clause, the packet is forwarded according to the routing table. IPv6 PBR matches the packet against the next node. No The packet is forwarded according to the routing table. IPv6 PBR matches the packet against the next node.
Step 2. Create an IPv6 policy or policy node, and enter IPv6 policy node view. Command Remarks ipv6 policy-based-route policy-name [ deny | permit ] node node-number By default, no IPv6 policy node is created. Configuring match criteria for an IPv6 node Step Command Remarks 1. Enter system view. system-view N/A 2. Enter IPv6 policy node view. ipv6 policy-based-route policy-name [ deny | permit ] node node-number N/A 3. Configure an ACL match criterion.
To configure IPv6 interface PBR: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter interface view. interface interface-type interface-number N/A 3. Apply an IPv6 policy to the interface. ipv6 policy-based-route policy-name By default, no IPv6 policy is applied to the interface. Displaying and maintaining IPv6 PBR Execute display commands in any view and reset commands in user view. Task Command Display IPv6 PBR policy information.
Figure 83 Network diagram Configuration procedure 1. Configure Switch A: # Configure RIPng.
# Configure IPv6 interface PBR by applying the policy aaa to VLAN-interface 11. [SwitchA] interface vlan-interface 11 [SwitchA-Vlan-interface11] ipv6 address 10::2 64 [SwitchA-Vlan-interface11] undo ipv6 nd ra halt [SwitchA-Vlan-interface11] ripng 1 enable [SwitchA-Vlan-interface11] ipv6 policy-based-route aaa 2. Configure RIPng on Switch B.
Configuring routing policies Routing policies control routing paths by filtering and modifying routing information. This chapter describes both IPv4 and IPv6 routing policies. Overview Routing policies can filter advertised, received, and redistributed routes, and modify attributes for specific routes. To configure a routing policy: 1. Configure filters based on route attributes, such as destination address and the advertising router's address. 2.
For more information about community lists, see "Configuring BGP." Extended community list An extended community list matches the extended community attribute (for example, Route-Target for VPN) of BGP routing information. For more information about extended community lists, see MPLS Configuration Guide. Routing policy A routing policy can comprise multiple nodes, which are in a logical OR relationship. A node with a smaller number is matched first.
Configuring filters Configuration prerequisites Determine the IP prefix list name, matching address range, and community list number. Configuring an IP prefix list Configuring an IPv4 prefix list If all the items are set to deny mode, no routes can pass the IPv4 prefix list. To allow other IPv4 routing information to pass, you must configure the permit 0.0.0.0 0 less-equal 32 item following multiple deny items. To configure an IPv4 prefix list: Step Command Remarks 1. Enter system view.
Step Command Remarks 1. Enter system view. system-view N/A 2. Configure an AS path list. ip as-path as-path-number { deny | permit } regular-expression By default, no AS path list is configured. Configuring a community list You can configure multiple items for a community list that is identified by number. The relationship between the items is logic OR. A route that matches one item matches the community list. To configure a community list: Step 1. Enter system view.
Configuring a routing policy Configuration prerequisites Configure filters and routing protocols, and determine the routing policy name, node numbers, match criteria, and the attributes to be modified. Creating a routing policy For a routing policy that has more than one node, configure at least one permit-mode node. A route that does not match any node cannot pass the routing policy. If all the nodes are in deny mode, no routing information can pass the routing policy.
Step 3. Match routes whose destination, next hop, or source matches a specified prefix list. Command Remarks • Match IPv4 routes whose By default, no IPv4 or IPv6 prefix list match criterion is configured.
Configuring apply clauses Except for the apply commands used for setting the next hop for IPv4 and IPv6 routes, all apply commands are the same for IPv4 and IPv6 routing. To configure apply clauses: Step Command Remarks 1. Enter system view. system-view N/A 2. Enter routing policy node view. route-policy route-policy-name { deny | permit } node node-number N/A 3. Set the AS_PATH attribute for BGP routes.
Step Command Remarks 13. Set the ORIGIN attribute for BGP routes. apply origin { egp as-number | igp | incomplete } By default, no ORIGIN attribute is set for BGP routes. 14. Set a preference. apply preference preference By default, no preference is set. 15. Set a preferred value for BGP routes. apply preferred-value preferred-value By default, no preferred value is set for BGP routes. 16. Set a tag value for RIP, OSPF, and IS-IS route.
Task Command Display BGP AS path list information. display ip as-path [ as-path-number ] Display BGP community list information. display ip community-list [ basic-community-list-number | adv-community-list-number | comm-list-name ] Display BGP extended community list information. display ip extcommunity-list [ ext-comm-list-number ] Display IPv4 prefix list statistics. display ip prefix-list [ prefix-list-name ] Display IPv6 prefix list statistics.
system-view [SwitchC] isis [SwitchC-isis-1] is-level level-2 [SwitchC-isis-1] network-entity 10.0000.0000.0001.
Routing for Network Destination Cost Type NextHop AdvRouter Area 192.168.1.0/24 1 Stub 192.168.1.1 192.168.1.1 0.0.0.0 Destination Cost Type Tag NextHop AdvRouter 172.17.1.0/24 1 Type2 1 192.168.1.2 192.168.2.2 172.17.2.0/24 1 Type2 1 192.168.1.2 192.168.2.2 172.17.3.0/24 1 Type2 1 192.168.1.2 192.168.2.2 Routing for ASEs Total Nets: 4 Intra Area: 1 4. Inter Area: 0 ASE: 3 NSSA: 0 Configure filtering lists: # Configure ACL 2002 to permit route 172.17.2.0/24.
Routing for ASEs Destination Cost Type Tag NextHop AdvRouter 172.17.1.0/24 100 Type2 1 192.168.1.2 192.168.2.2 172.17.2.0/24 1 Type2 20 192.168.1.2 192.168.2.2 172.17.3.0/24 1 Type2 1 192.168.1.2 192.168.2.2 Total Nets: 4 Intra Area: 1 Inter Area: 0 ASE: 3 NSSA: 0 The output shows that the cost of route 172.17.1.0/24 is 100 and the tag of route 172.17.2.0/24 is 20.
[SwitchA] ipv6 route-static 40:: 32 11::2 # Configure a routing policy. [SwitchA] ipv6 prefix-list a index 10 permit 30:: 32 [SwitchA] route-policy static2ripng deny node 0 [SwitchA-route-policy-static2ripng-0] if-match ipv6 address prefix-list a [SwitchA-route-policy-static2ripng-0] quit [SwitchA] route-policy static2ripng permit node 10 [SwitchA-route-policy-static2ripng-10] quit # Enable RIPng and apply the routing policy to static route redistribution.
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Conventions This section describes the conventions used in this documentation set. Command conventions Convention Description Boldface Bold text represents commands and keywords that you enter literally as shown. Italic Italic text represents arguments that you replace with actual values. [] Square brackets enclose syntax choices (keywords or arguments) that are optional. { x | y | ... } Braces enclose a set of required syntax choices separated by vertical bars, from which you select one.
Network topology icons Represents a generic network device, such as a router, switch, or firewall. Represents a routing-capable device, such as a router or Layer 3 switch. Represents a generic switch, such as a Layer 2 or Layer 3 switch, or a router that supports Layer 2 forwarding and other Layer 2 features. Represents an access controller, a unified wired-WLAN module, or the switching engine on a unified wired-WLAN switch. Represents an access point.
Index 4-byte IPv4 BGP AS number suppression, 218 IPv4 BGP COMMUNITY configuration, 225, 247 IPv6 BGP AS number suppression, 218 IPv4 BGP confederation configuration, 253 IPv4 BGP configuration, 234 ABR OSPF route summarization on ABR, 65 IPv4 BGP fake AS number advertisement, 211 OSPF router type, 53 IPv4 BGP GR configuration, 261 IPv4 BGP load balancing configuration, 244 action IPv4 BGP path selection configuration, 257 PBR node, 280 IPv4 BGP route reflector configuration, 251 address IS-IS ar
routing policy apply clause configuration, 363 IPv4 BGP confederation configuration, 253 routing policy to IPv4 route redistribution, 365 IPv4 BGP configuration, 234 routing policy to IPv6 route redistribution, 368 IPv4 BGP fake AS number advertisement, 211 IPv4 BGP GR configuration, 261 area IS-IS, 114 IPv4 BGP load balancing configuration, 244 IS-IS area address, 113 IPv4 BGP local AS number appearance, 209 IS-IS area authentication, 137 IPv4 BGP MED AS route (confederation peers), 206 OSPF ar
OSPF AS External LSA, 50 IPv6 BGP AS_PATH best route selection, 210 routing policy AS_PATH list, 357 IPv6 BGP fake AS number advertisement, 211 routing policy AS_PATH list configuration, 359 IPv6 BGP MED AS route (confederation peers), 206 AS_PATH comparison IPv6 BGP MED AS route comparison (diff ASs), 204 BGP attribute configuration, 209 IPv4 BGP best route selection, 210 IPv6 BGP MED AS route comparison (per-AS), 205 IPv6 BGP best route selection, 210 ASBR IPv6 BGP MED default value, 203 OSPF
community, 171 OSPF reference value, 66 confederation, 171 BDR OSPF, 55 confederation compatibility, 228 OSPF election, 56 confederation configuration, 228 configuration, 164, 177 BFD bidirectional control mode, 7 configuration views, 175 configuration guideline, 9 default route advertisement to peer/peer group, 193 configuring static route, 7 EBGP direct connections after link failure, 217 IPv4 BGP configuration, 230, 262 enabling, 179 IPv6 BGP configuration, 230, 272 first AS number of EBG
route dampening, 171 OSPF FRR backup next hop calculation, 82 route distribution control, 190 OSPF interface cost, 66 route filtering policies, 194 OSPF route calculation, 54 route generation, 188 OSPF SPF calculation interval, 72 route reception control, 190 OSPFv3 SPF calculation interval, 319 checking route recursion, 170 OSPFv3 DD packet ignore MTU check, 321 route reflector, 171 route selection, 169, 170 classless inter-domain routing.
IPv4 BGP confederation configuration, 253 IPv4 BGP BFD, 230, 262 IPv4 BGP MED AS route (confederation peers), 206 comparison IPv4 BGP COMMUNITY, 225, 247 IPv6 BGP MED AS route (confederation peers), 206 comparison IPv4 BGP confederation, 253 IPv4 BGP default local preference, 202 IPv4 BGP GR, 261 configuration IPv4 BGP holdtime, 214 default route, 19 IPv4 BGP keepalive interval, 214 guideline, 9 IPv4 BGP load balancing, 218, 244 prerequisites, RIP route control, 28 IPv4 BGP manual soft reset,
IPv6 BGP MED default value, 203 IS-IS area authentication, 137 IPv6 BGP NEXT_HOP attribute, 207 IS-IS authentication, 153 IPv6 BGP peer, 181 IS-IS basics, 141 IPv6 BGP route automatic summarization, 191 IS-IS BFD, 157 IPv6 BGP route dampening, 199 IS-IS circuit level, 121 IPv6 BGP route distribution filtering policies, 195 IS-IS DIS election, 146 IPv6 BGP route manual summarization, 191 IS-IS ECMP routes max number, 125 IPv6 BGP route preference, 201 IS-IS FRR, 139, 160 IPv6 BGP route recept
OSPF route redistribution from different routing protocol, 68 OSPF authentication, 74 OSPF basics, 84 OSPF route summarization, 65 OSPF BFD, 80, 105 OSPF route summarization on ABR, 65 OSPF BFD bidirectional control detection, 80 OSPF stub area, 60, 92 OSPF BFD single-hop echo detection, 81 OSPF stub router, 74 OSPF broadcast network type for interface, 62 OSPF summary route advertisement, 88 OSPF DD packet interface MTU, 75 OSPF timer, 70 OSPF default route redistribution, 69 OSPF Type-3 LSA
PBR, 278, 279, 280 RIPng split horizon, 300 PBR node action, 280 RIPng timer, 300 PBR node match criteria, 280 RIPv2 message authentication, 31 PBR packet type-based interface PBR, 281 RIPv2 route summarization, 25 PBR policy, 279 route recursion, 4 RIP, 20, 22, 35 routing policy, 357, 361 RIP additional routing metric, 24 routing policy apply clause, 363 RIP basics, 22, 35 routing policy AS_PATH list, 359 RIP BFD, 33 routing policy community list, 360 RIP BFD single-hop echo detection, 43
default route OSPFv3 route control configuration, 314 configuration details, 19 RIP additional routing metric configuration, 24 delaying RIP interface advertisement, 23 OSPFv3 LSA transmission delay, 319 RIP interface reception, 23 detecting RIP route control configuration, 24 configuring RIP BFD single-hop echo detection, 43 RIPng route control, 297 convergence priority (IS-IS), 133 IPv4 BGP BFD configuration, 230 cost IPv6 BGP BFD configuration, 230 OSPFv3 interface cost configuration, 316
IPv6 static routing BFD (direct next hop, 289 RIP interface additional metric configuration, 39 IPv6 static routing BFD (indirect next hop, 291 RIP route redistribution configuration, 37 IS-IS authentication, 153 RIP summary route advertisement configuration, 41 IS-IS basic configuration, 141 RIPng basic configuration, 302 IS-IS BFD configuration, 157 RIPng configuration, 302 IS-IS DIS election configuration, 146 RIPng route redistribution, 305 IS-IS FRR configuration, 160 IS-IS GR configuration
peer, 164 PBR, 281 echo RIP, 34 IPv6 static route BFD echo mode (single hop), 286 RIPng, 302 routing policy, 364, 365 OSPF BFD single-hop echo detection, 80, 81 static routes, 10 single-hop mode, 8 distributing ECMP.
extending IPv6 BGP MED AS route comparison (per-AS), 205 IPv6 BGP multiple establishment, 216 hop EBGP IS-IS LSP fragment extension, 132 session MP-BGP MP_REACH_NLRI extended attribute, 174 IPv6 BGP route refresh, 221 MP-BGP MP_UNREACH_NLRI attribute, 174 IS-IS, 121 IS-IS automatic cost calculation, 124 Exterior Gateway Protocol. See EGP IS-IS interface hello packet send, 130 external extended OSPF LSDB max number external LSAs, 75 IS-IS ISPF, 136 IS-IS LSP flash flooding, 132 external BGP.
IPv6 PBR packet type-based IPv6 interface PBR, 354 IS-IS redistributed routes, 127 IS-IS routes, 127 IPv6 policy configuration, 352 OSPF Type-3 LSA filtering, 66 OSPF GR configuration, 78 OSPFv3 Inter-Area-Prefix LSA filtering, 315 OSPF GR Helper configuration, 79 OSPFv3 received route filtering, 315 OSPF GR Restarter configuration, 78 RIPng received/redistributed route filtering, 298 OSPFv3 BFD configuration, 323 routing policy ACLs, 357 routing policy application redistribution, 365 to IPv4
IS-IS hello multiplier, 128 GR Helper IS-IS GR configuration, 137, 138 IS-IS hello packet send interval, 128 OSPF configuration, 79 IS-IS interface hello packet send, 130 OSPF GR configuration, 78 IS-IS PDU type, 118 OSPFv3 GR configuration, 322 OSPF hello packet, 49 OSPFv3 GR Helper configuration, 322 OSPF hello packet timer, 70 RIP GR Helper configuration, 32 OSPFv3 packet type, 309 HO-DSP (IS-IS area address), 113 RIPng, 301 holdtime GR Restarter IS-IS GR configuration, 137, 138 IPv4 BGP,
IS-IS CSNP packet send interval, 128 OSPF GR Restarter, 78 IS-IS hello multiplier, 128 ignoring BGP first AS number of EBGP route updates, 214 IS-IS hello packet send interval, 128 OSPFv3 DD packet MTU check, 321 IS-IS SPF calculation interval, 133 OSPF exit overflow interval, 75 IGP BGP ORIGIN path attribute, 165 OSPF LSA arrival interval, 72 configuring RIP BFD single-hop echo detection, 43 OSPF LSA generation interval, 73 OSPF LSU transmit rate, 77 IPv4 BGP-IGP route redistribution, 238 OSPF
BGP optimal route advertisement, 192 OSPF DD packet interface MTU, 75 BGP path selection, 200 OSPF FRR backup next hop calculation, 82 BGP peer configuration, 180 OSPF FRR backup next hop using routing policy, 82 BGP peer group, 171 OSPF FRR configuration, 81 BGP peer group configuration, 181 OSPF interface packet send/receive disable, 73 BGP route dampening, 171 OSPF stub router configuration, 74 BGP route distribution, 190 OSPF timer configuration, 70 BGP route filtering policies, 194 OSPFv
OSPFv3 route control configuration, 314 RIPng packet zero field check configuration, 301 OSPFv3 route redistribution, 317, 332 RIPng poison reverse configuration, 300 OSPFv3 route summarization, 315 RIPng preference, 299 OSPFv3 SPF calculation interval, 319 RIPng received/redistributed route filtering, 298 OSPFv3 stub area configuration, 312 RIPng route control configuration, 297 OSPFv3 timer configuration, 318 RIPng route entry, 295 OSPFv3 virtual link configuration, 313 RIPng route redistribu
IS-IS enable, 121 load balancing, 218 OSPF basic configuration, 84 load balancing configuration, 244 OSPF BFD configuration, 105 local AS number appearance, 209 OSPF configuration, 49, 57, 84 local network injection, 188 OSPF DR election configuration, 96 maintaining, 231 OSPF FRR configuration, 108 manual soft reset configuration, 223 OSPF GR configuration, 103 MED AS route comparison (confederation peers), 206 OSPF NSSA area configuration, 94 MED AS route comparison (diff ASs), 204 OSPF ro
IS-IS. See IPv6 IS-IS policy-based routing. See IPv6 PBR OSPFv3 area configuration, 324 RIP.
Track collaboration, 352 route automatic summarization, 191 IPv6 static routing route dampening, 199 route distribution filtering policies, 195 basic configuration, 287 route manual summarization, 191 BFD configuration (direct next hop, 289 route preference, 201 BFD configuration (indirect next hop, 291 route reception filtering policies, 197 configuration, 284 route reflector configuration, 227, 269 default route configuration, 294 route refresh configuration, 221 displaying, 286 route updat
FRR configuration using routing policy, 140 PDU SNP type, 118 global cost configuration, 124 PDU types, 118 GR configuration, 137, 138, 156 point-to-point network type, 116 hello multiplier, 128 preference specification, 124 hello packet send interval, 128 protocols and standards, 119 interface cost configuration, 123 pseudonode, 117 interface DIS priority, 129 redistributed route filtering, 127 interface hello packet send enable, 130 route advertisement configuration, 127 interface P2P netw
IPv6 BGP, 218 IPv6 EBGP peer protection (level 2 threshold exemption), 224 OSPF ECMP route max number, 67 limiting OSPFv3 max number ECMP routes, 316 IPv4 BGP routes received from peer/peer group, 193 RIPng max number ECMP routes, 301 load sharing IPv6 BGP routes received from peer/peer group, 193 IP routing load sharing, 3 IS-IS ECMP routes max number, 125 link RIP max number ECMP routes, 30 EBGP direct connection after link failure, 217 local IPv4 BGP BFD configuration, 230 IPv6 BGP BFD confi
OSPFv3 grace LSA, 309 IPv6 PBR, 354 OSPFv3 inter-area-prefix LSA, 309 IS-IS, 140 OSPFv3 Inter-Area-Prefix LSA filtering, 315 OSPF, 83 OSPFv3 inter-area-router LSA, 309 PBR, 281 OSPFv3 intra-area-prefix LSA, 309 RIP, 34 OSPFv3 link LSA, 309 RIPng, 302 OSPFv3 LSA generation interval, 320 routing policy, 364, 365 OSPFv3 LSA transmission delay, 319 static routes, 10 managing OSPFv3 network LSA, 309 BGP large scale network management, 171 OSPFv3 router LSA, 309 manual LSAck OSPF LSAck packet,
MP-BGP.
BGP route distribution, 190 neighbor IPv4 BGP BFD configuration, 230 BGP route filtering policies, 194 IPv6 BGP BFD configuration, 230 BGP route generation, 188 IS-IS neighbor state change logging, 135 BGP route reception, 190 OSPF neighbor state change logging, 76 BGP route recursion, 170 BGP route reflector, 171 neighbor discovery OSPFv3 area configuration, 324 BGP route selection, 169, 170 OSPFv3 BFD configuration, 336 BGP route summarization, 171, 191 OSPFv3 configuration, 309, 310, 324 BG
IPv4 BGP local AS number appearance, 209 IPv6 BGP received route preferred value, 200 IPv4 BGP local network injection, 188 IPv6 BGP route dampening, 199 IPv4 BGP manual soft reset, 223 IPv6 BGP route distribution filtering policies, 195 IPv4 BGP multiple establishment, 216 hop EBGP IPv6 BGP route preference, 201 session IPv6 BGP route reception filtering policies, 197 IPv4 BGP NEXT_HOP attribute, 207 IPv6 BGP route reflector configuration, 227 IPv4 BGP private AS number removal, 213 IPv6 BGP
optimizing IS-IS network, 128 IS-IS FRR automatic backup next hop calculation, 140 OSPF area configuration, 60 IS-IS FRR configuration, 139 OSPF BFD bidirectional control detection, 80 IS-IS FRR configuration using routing policy, 140 OSPF BFD configuration, 80 IS-IS global cost configuration, 124 OSPF BFD single-hop echo detection, 81 IS-IS GR configuration, 137, 138 IS-IS hello multiplier, 128 OSPF broadcast network type configuration for interface, 62 IS-IS hello packet send interval, 128 OSP
OSPFv3 max number ECMP routes, 316 OSPF P2MP network type configuration for interface, 63 OSPFv3 NBMA neighbor configuration, 314 OSPF P2P network type configuration for interface, 64 OSPFv3 neighbor state change logging, 321 OSPFv3 network type configuration, 313 OSPF preference, 68 OSPF redistributed route default parameters, 69 OSPFv3 network interface), 314 type configuration OSPF redistributed route summarization on ASBR, 65 OSPFv3 P2MP neighbor configuration, 314 (for OSPFv3 preference con
RIP preference configuration, 27 routing policy creation, 361 RIP route control configuration, 24 routing policy extended configuration, 360 RIP route entries, 20 community list routing policy filter configuration, 359 RIP route redistribution configuration, 28, 37 routing policy if-match clause configuration, 361 RIP routing loop prevention, 20 routing policy IP prefix list configuration, 359 RIP split horizon configuration, 29 tuning BGP, 214 RIP summary route advertisement configuration, 41
IPv6 static routing BFD (indirect next hop, 291 RIPng GR configuration, 301 IPv6 static routing configuration, 284 RIPng network optimization, 299 IS-IS authentication, 153 RIPng network tuning, 299 IS-IS basic configuration, 121, 141 RIPng route redistribution, 305 IS-IS BFD configuration, 157 routing policy application redistribution, 365 to IPv4 route routing policy application redistribution, 368 to IPv6 route IS-IS configuration, 112, 120 IS-IS DIS election configuration, 146 IS-IS FRR
PBR/Track collaboration, 279 Open Shortest Path First. Use OSPF routing policy apply clause, 358 Open Shortest Path First version 3.
FRR backup next hop calculation, 82 redistributed route default parameters, 69 FRR backup next hop using routing policy, 82 redistributed route summarization on ASBR, 65 FRR configuration, 81, 108 RFC 1583 compatibility, 76 GR configuration, 78, 103 route calculation, 54 GR Helper configuration, 79 route control configuration, 64 GR Restarter configuration, 78 route redistribution, 87 GR trigger, 80 route redistribution configuration, 68 host route advertisement, 70 route redistribution proto
P2P DR election configuration, 328 enable, 311 OSPF network type, 54 GR configuration, 322, 335 OSPF network type configuration, 62 GR Helper configuration, 322 OSPF network type configuration for interface, 64 GR Restarter configuration, 322 OSPFv3 network type configuration, 313 Inter-Area-Prefix LSA filtering, 315 OSPFv3 network interface), 314 interface cost configuration, 316 interface DR priority, 320 type configuration (for P2P network type (IS-IS), 122 interface packet send/receive d
OSPF BFD configuration, 80 PBR policy configuration, 279 OSPF configuration, 49, 57 RIP packet send rate configuration, 32 OSPF DD, 49 RIPng, 296 OSPF DD packet interface MTU, 75 RIPng packet zero field check, 301 OSPF exit overflow interval, 75 specifying IS-IS CSNP packet send interval, 128 packets OSPF FRR configuration, 81 forwarding when routing table has no matching entry, 19 OSPF GR configuration, 78 OSPF GR Helper configuration, 79 parameter OSPF GR Restarter configuration, 78 IS-IS L
configuration, 278, 279, 280 IPv6 EBGP peer group configuration, 183 displaying, 281 IPv6 EBGP peer protection (low memory exemption), 224 maintaining, 281 IPv6 IBGP peer group configuration, 181 node action configuration, 280 permitting node creation, 279 IPv4 BGP local AS number appearance, 209 node match criteria, 280 point-to-point IS-IS network type, 116 packet type-based interface configuration, 281 poison reverse, 29, 30 policy, 278 RIPng configuration, 300 policy configuration, 279
OSPFv3 interface DR priority, 320 routing policy AS_PATH list configuration, 359 procedure routing policy community list configuration, 360 advertising BGP default route to peer/peer group, 193 routing policy configuration, 357, 361 routing policy continue clause configuration, 364 advertising IPv4 BGP fake AS number, 211 advertising IPv6 BGP fake AS number, 211 routing policy creation, 361 routing policy extended configuration, 360 community advertising IS-IS default route, 126 list advertising
configuring IPv4 BGP, 234 configuring IPv6 BGP basics, 266 configuring IPv4 BGP AS number substitution, 212 configuring IPv6 BGP BFD, 230, 272 configuring IPv6 BGP COMMUNITY, 225 configuring IPv4 BGP basics, 234 configuring IPv4 BGP BFD, 230, 262 configuring IPv6 BGP default local preference, 202 configuring IPv4 BGP COMMUNITY, 225, 247 configuring IPv6 BGP holdtime, 214 configuring IPv4 BGP confederation, 253 configuring IPv6 BGP keepalive interval, 214 configuring IPv4 BGP default local preferen
configuring IS-IS route convergence priority, 133 configuring IPv6 static route BFD control mode (indirect next hop), 285 configuring IS-IS route filtering, 127 configuring IPv6 static route BFD echo mode (single hop), 286 configuring IS-IS route redistribution, 126, 150 configuring IS-IS route summarization, 125 configuring IPv6 static routing basics, 287 configuring IS-IS routing domain authentication, 137 configuring IPv6 static routing BFD (direct next hop, 289 configuring IS-IS system ID-host n
configuring OSPF interface cost, 66 configuring OSPFv3 GR, 322, 335 configuring OSPF LSDB max number external LSAs, 75 configuring OSPFv3 GR Helper, 322 configuring OSPFv3 GR Restarter, 322 configuring OSPF LSU transmit rate, 77 configuring OSPFv3 filtering, 315 configuring OSPF max number ECMP routes, 67 Inter-Area-Prefix LSA configuring OSPFv3 interface cost, 316 configuring OSPF NBMA network type for interface, 63 configuring OSPFv3 interface DR priority, 320 configuring OSPF network manageme
configuring routing policy extended community list, 360 configuring RIP interface additional metric, 39 configuring RIP max number ECMP routes, 30 configuring routing policy filter, 359 configuring RIP packet send rate, 32 configuring routing policy if-match clause, 361 configuring RIP poison reverse, 29 configuring routing policy IP prefix list, 359 configuring RIP preference, 27 configuring routing policy IPv4 prefix list, 359 configuring RIP route control, 24 configuring routing policy IPv6 pre
displaying IS-IS, 140 enabling IS-IS interface hello packet send, 130 displaying OSPF, 83 enabling IS-IS ISPF, 136 displaying OSPFv3, 323 enabling IS-IS LSP flash flooding, 132 displaying PBR, 281 enabling IS-IS LSP fragment extension, 132 displaying RIP, 34 enabling IS-IS neighbor state change logging, 135 displaying RIPng, 302 enabling OSPF, 58 displaying routing policy, 364, 365 enabling OSPF ISPF, 78 displaying static routing, 10 enabling OSPF neighbor state change logging, 76 enabling B
maintaining OSPF, 83 specifying IS-IS preference, 124 maintaining PBR, 281 specifying OSPF LSA arrival interval, 72 maintaining RIP, 34 specifying OSPF LSA generation interval, 73 maintaining RIPng, 302 specifying OSPF LSA transmission delay, 71 maintaining routing policy, 364, 365 specifying OSPF SPF calculation interval, 72 maintaining static routing, 10 specifying OSPFv3 LSA generation interval, 320 optimizing BGP network, 214 specifying OSPFv3 LSA transmission delay, 319 optimizing IS-IS n
BGP route recursion, 170 interface advertisement control, 23 IP routing route recursion, 4 interface reception control, 23 IPv6.
BGP default route advertisement to peer/peer group, 193 max number ECMP routes, 301 network optimization, 299 BGP optimal route advertisement rules, 192 network tuning, 299 BGP route advertisement rules, 170 packet, 296 BGP route dampening, 171 packet zero field check, 301 BGP route filtering policies, 194 poison reverse configuration, 300 BGP route generation, 188 preference configuration, 299 BGP route recursion, 170 protocols and standards, 296 BGP route reflector, 171 received/redistribut
IS-IS route filtering, 127 IPv4 BGP routes received from peer/peer group, 193 IS-IS route leaking configuration, 127 IPv4 BGP-IGP route redistribution, 238 IS-IS route redistribution, 126, 150 IPv6 BGP IGP route redistribution, 189 IPv6 BGP MED AS route (confederation peers), 206 IS-IS route summarization, 125 comparison OSPF default route redistribution, 69 OSPF ECMP route max number configuration, 67 IPv6 BGP MED AS route comparison (diff ASs), 204 OSPF host route advertisement, 70 IPv6 BGP MED
RIP route redistribution configuration, 28, 37 IPv6 IS-IS BFD configuration, 347 RIP split horizon configuration, 29 IPv6 IS-IS configuration, 343 RIP update source IP address check, 31 IPv6 PBR packet type-based IPv6 interface PBR, 354 RIPng default route advertisement, 298 IPv6 static routing basics, 287 RIPng max number ECMP routes, 301 IPv6 static routing BFD (direct next hop), 289 RIPng preference, 299 IPv6 static routing BFD (indirect next hop), 291 RIPng received/redistributed route filte
RIP basic configuration, 35 IS-IS GR configuration, 137, 138, 156 RIP FRR configuration, 46 IS-IS hello multiplier, 128 RIP interface additional metric configuration, 39 IS-IS hello packet send interval, 128 RIP route redistribution configuration, 37 IS-IS interface cost configuration, 123 RIP summary route advertisement configuration, 41 IS-IS interface DIS priority, 129 IS-IS interface hello packet send, 130 RIPng basic configuration, 302 IS-IS interface packet send/receive, 129 routing policy
IS-IS system ID-host name mapping (static), 134 OSPF preference, 68 maintaining policy, 364, 365 OSPF redistributed route default parameters, 69 MP-BGP, 174 OSPF redistributed route summarization on ASBR, 65 optimizing IS-IS networks, 128 OSPF route control configuration, 64 OSPF area configuration, 60 OSPF route redistribution, 68, 87 OSPF basic configuration, 84 OSPF route redistribution from different routing protocol, 68 OSPF BFD bidirectional control detection, 80 OSPF BFD configuration, 80
policy IP prefix list configuration, 359 RIPng network tuning, 299 policy-based routing.
OSPF LSA transmission delay, 71 selecting BGP path selection, 200 OSPF SPF calculation interval, 72 BGP route, 169 OSPFv3 LSA generation interval, 320 BGP route selection, 170 OSPFv3 LSA transmission delay, 319 IPv4 BGP path selection configuration, 257 OSPFv3 SPF calculation interval, 319 SPF session IS-IS calculation interval, 133 BGP session state change logging, 230 IPv4 BGP multiple establishment, 216 hop EBGP OSPF SPF calculation interval, 72 session OSPFv3 SPF calculation interval, 31
OSPF configuration, 84 stub OSPF stub area, 52 OSPF DR election configuration, 96 OSPF stub area configuration, 60, 92 OSPF FRR configuration, 108 OSPF stub router configuration, 74 OSPF GR configuration, 103 OSPF totally stub area, 52 OSPF NSSA area configuration, 94 OSPFv3 stub area configuration, 312 OSPF route redistribution, 87 OSPF stub area configuration, 92 substituting IPv4 BGP AS number substitution, 212 OSPF summary route advertisement, 88 IPv6 BGP AS number substitution, 212 OSPF v
IPv6 BGP basic configuration, 266 IPv6 static routing configuration, 284 IPv6 BGP BFD configuration, 272 IS-IS ISPF, 136 Track IPv6 BGP configuration, 266 IPv6 PBR collaboration, 352 IPv6 BGP route reflector configuration, 269 PBR collaboration, 279 threshold static route, 6 IPv4 EBGP peer protection (level 2 threshold exemption), 224 trapping IPv6 EBGP peer protection (level 2 threshold exemption), 224 OSPF network management, 77 triggering time OSPF GR, 80 IPv4 BGP holdtime, 214 troublesh
IP routing ECMP configuration, 4 route max IPv4 BGP route update, 222 number IPv4 BGP route update interval, 216 IP routing load sharing, 3 IPv6 BGP route update, 222 IP routing route backup, 3 IPv6 BGP route update interval, 216 IP routing route preference, 3 value IP routing route recursion, 4 BGP received route preferred value, 200 IP routing route redistribution, 4 IPv4 BGP MED default value, 203 OSPF network type, 54 IPv6 BGP MED default value, 203 update timer, 28 zero field check
