BFD for IPv6 static routes configuration example (indirect next hop)

Network requirements

In Figure 76, Switch A has a route to interface Loopback 1 (2::9/128) on Switch B, with the output interface being VLAN-interface 10. Switch B has a route to interface Loopback 1 (1::9/128) on Switch A, with the output interface being VLAN-interface 12. Switch D has a route to 1::9/128, with the output interface being VLAN-interface 10, and a route to 2::9/128, with the output interface being VLAN-interface 12.

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 both Switch C and Switch D. When the link between Switch A and Switch B through Switch D fails, BFD can detect the failure immediately and Switch A and Switch B can communicate through Switch C.

Figure 76: Network diagram

Device

Interface

IPv6 address

Device

Interface

IPv6 address

Switch A

Vlan-int10

12::1/64

Switch B

Vlan-int12

11::2/64

Vlan-int11

10::102/64

Vlan-int13

13::1/64

Loop1

1::9/128

Loop1

2::9/128

Switch C

Vlan-int11

10::100/64

Switch D

Vlan-int10

12::2/64

Vlan-int13

13::2/64

Vlan-int12

11::1/64

Configuration procedure

  1. Configure IPv6 addresses for interfaces. (Details not shown.)

  2. Configure IPv6 static routes and BFD:

    # Configure IPv6 static routes on Switch A and enable BFD control packet mode for the IPv6 static route that traverses Switch D.

    <SwitchA> system-view
    [SwitchA] interface loopback 1
    [SwitchA-LoopBack1] bfd min-transmit-interval 500
    [SwitchA-LoopBack1] bfd min-receive-interval 500
    [SwitchA-LoopBack1] bfd detect-multiplier 9
    [SwitchA-LoopBack1] quit
    [SwitchA] ipv6 route-static 120:: 64 2::9 bfd control-packet bfd-source 1::9
    [SwitchA] ipv6 route-static 120:: 64 10::100 preference 65
    [SwitchA] quit
    

    # Configure IPv6 static routes on Switch B and enable BFD control packet mode for the static route that traverses Switch D.

    <SwitchB> system-view
    [SwitchB] interface loopback 1
    [SwitchB-LoopBack1] bfd min-transmit-interval 500
    [SwitchB-LoopBack1] bfd min-receive-interval 500
    [SwitchB-LoopBack1] bfd detect-multiplier 9
    [SwitchB-LoopBack1] quit
    [SwitchB] ipv6 route-static 121:: 64 1::9 bfd control-packet bfd-source 2::9
    [SwitchB] ipv6 route-static 121:: 64 13::2 preference 65
    [SwitchB] quit
    

    # Configure IPv6 static routes on Switch C.

    <SwitchC> system-view
    [SwitchC] ipv6 route-static 120:: 64 13::1
    [SwitchC] ipv6 route-static 121:: 64 10::102
    

    # Configure IPv6 static routes on Switch D.

    <SwitchD> system-view
    [SwitchD] ipv6 route-static 120:: 64 11::2
    [SwitchD] ipv6 route-static 121:: 64 12::1
    

Verifying the configuration

# Display the BFD sessions on Switch A.

<SwitchA> display bfd session

 Total Session Num: 1     Up Session Num: 1     Init Mode: Active

 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: N/A
         Hold Time: 2012ms

The output shows that the BFD session has been created.

# Display the IPv6 static routes on Switch A.

<SwitchA> display ipv6 routing-table protocol static

Summary Count : 1

Static Routing table Status : <Active>
Summary Count : 1

Destination: 120::/64                                    Protocol  : Static
NextHop    : 2::9                                        Preference: 60
Interface  : Vlan10                                      Cost      : 0

Static Routing table Status : <Inactive>
Summary Count : 0

The output shows that Switch A communicates Switch B through VLAN-interface 10. The link over VLAN-interface 10 fails.

# Display IPv6 static routes on Switch A again.

<SwitchA> display ipv6 routing-table protocol static

Summary Count : 1

Static Routing table Status : <Active>
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.