OSPFv3 FRR configuration example

Network requirements

As shown in Figure 111, Switch A, Switch B, and Switch C reside in the same OSPFv3 domain. Configure OSPFv3 FRR so that when Link A fails, traffic is immediately switched to Link B.

Figure 111: Network diagram

Table 27: Interface and IP address assignment

Device

Interface

IP address

Device

Interface

IP address

Switch A

Vlan-int100

1::1/64

Switch B

Vlan-int101

3::1/64

Vlan-int200

2::1/64

Vlan-int200

2::2/64

Loop0

10::1/128

Loop0

20::1/128

Switch C

Vlan-int100

1::2/64

Vlan-int101

3::2/64

Configuration procedure

  1. Configure IPv6 addresses and subnet masks for interfaces on the switches. (Details not shown.)

  2. Configure OSPFv3 on the switches to ensure that Switch A, Switch B, and Switch C can communicate with each other at the network layer. (Details not shown.)

  3. Configure OSPFv3 FRR to automatically calculate the backup next hop:

    You can enable OSPFv3 FRR to either calculate a backup next hop by using the LFA algorithm, or specify a backup next hop by using a routing policy.

    • (Method 1.) Enable OSPFv3 FRR to calculate the backup next hop by using the LFA algorithm:

      # Configure Switch A.

      <SwitchA> system-view
      [SwitchA] ospfv3 1
      [SwitchA-ospfv3-1] fast-reroute lfa
      [SwitchA-ospfv3-1] quit
      

      # Configure Switch B.

      <SwitchB> system-view
      [SwitchB] ospfv3 1
      [SwitchB-ospfv3-1] fast-reroute lfa
      [SwitchB-ospfv3-1] quit
      
    • (Method 2.) Enable OSPFv3 FRR to designate a backup next hop by using a routing policy:

      # Configure Switch A.

      <SwitchA> system-view
      [SwitchA] ipv6 prefix-list abc index 10 permit 10:: 128
      [SwitchA] route-policy frr permit node 10
      [SwitchA-route-policy-frr-10] if-match ipv6 address prefix-list abc
      [SwitchA-route-policy-frr-10] apply ipv6 fast-reroute backup-interface vlan-interface 100 backup-nexthop 1::2/64
      [SwitchA-route-policy-frr-10] quit
      [SwitchA] ospfv3 1
      [SwitchA-ospfv3-1] fast-reroute route-policy frr
      [SwitchA-ospfv3-1] quit
      

      # Configure Switch B.

      <SwitchB> system-view
      [SwitchB] ipv6 prefix-list abc index 10 permit 20:: 128
      [SwitchB] route-policy frr permit node 10
      [SwitchB-route-policy-frr-10] if-match ipv6 address prefix-list abc
      [SwitchB-route-policy-frr-10] apply ipv6 fast-reroute backup-interface vlan-interface 101 backup-nexthop 3::2/64
      [SwitchB-route-policy-frr-10] quit
      [SwitchB] ospfv3 1
      [SwitchB-ospfv3-1] fast-reroute route-policy frr
      [SwitchB-ospfv3-1] quit
      

Verifying the configuration

# Display the route 20::1/128 on Switch A to view the backup next hop information.

[SwitchA] display ipv6 routing-table 20::1 128 verbose

Summary count : 1

Destination: 20::1/128
   Protocol: O_INTRA
 Process ID: 1
  SubProtID: 0x1                    Age: 00h03m45s
       Cost: 6               Preference: 10
      IpPre: N/A             QosLocalID: N/A
        Tag: 0                    State: Active Adv
  OrigTblID: 0x0                OrigVrf: default-vrf
    TableID: 0xa                 OrigAs: 0
      NibID: 0x23000005          LastAs: 0
     AttrID: 0xffffffff        Neighbor: ::
      Flags: 0x10041        OrigNextHop: FE80::7685:45FF:FEAD:102
      Label: NULL           RealNextHop: FE80::7685:45FF:FEAD:102
    BkLabel: NULL             BkNextHop: FE80::34CD:9FF:FE2F:D02
  Tunnel ID: Invalid          Interface: Vlan-interface200
BkTunnel ID: Invalid        BkInterface: Vlan-interface100
   FtnIndex: 0x0           TrafficIndex: N/A
  Connector: N/A

# Display the route 10::1/128 on Switch B to view the backup next hop information.

[SwitchB] display ipv6 routing-table 10::1 128 verbose

Summary count : 1

Destination: 10::1/128
   Protocol: O_INTRA
 Process ID: 1
  SubProtID: 0x1                    Age: 00h03m10s
       Cost: 1               Preference: 10
      IpPre: N/A             QosLocalID: N/A
        Tag: 0                    State: Active Adv
  OrigTblID: 0x0                OrigVrf: default-vrf
    TableID: 0xa                 OrigAs: 0
      NibID: 0x23000006          LastAs: 0
     AttrID: 0xffffffff        Neighbor: ::
      Flags: 0x10041        OrigNextHop: FE80::34CC:E8FF:FE5B:C02
      Label: NULL           RealNextHop: FE80::34CC:E8FF:FE5B:C02
    BkLabel: NULL             BkNextHop: FE80::7685:45FF:FEAD:102
  Tunnel ID: Invalid          Interface: Vlan-interface200
BkTunnel ID: Invalid        BkInterface: Vlan-interface101
   FtnIndex: 0x0           TrafficIndex: N/A
  Connector: N/A