Example: Configuring BFD for IPv6 IS-IS

Network configuration

As shown in Figure 53:

After the link between Switch B and the Layer 2 switch fails, BFD can quickly detect the failure and notify IPv6 IS-IS of the failure. Then Switch A and Switch B communicate through Switch C.

Figure 53: Network diagram

Table 16: Interface and IP address assignment

Device

Interface

IPv6 address

Device

Interface

IPv6 address

Switch A

Vlan-int10

2001::1/64

Switch B

Vlan-int10

2001::2/64

Vlan-int11

2001:2::1/64

Vlan-int13

2001:3::2/64

Switch C

Vlan-int11

2001:2::2/64

Vlan-int13

2001:3::1/64

Procedure


[IMPORTANT: ]

IMPORTANT:

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.


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

  2. Configure IPv6 IS-IS:

    # Configure Switch A.

    <SwitchA> 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] address-family ipv6
    [SwitchA-isis-1-ipv6] quit
    [SwitchA-isis-1] quit
    [SwitchA] interface vlan-interface 10
    [SwitchA-Vlan-interface10] isis ipv6 enable 1
    [SwitchA-Vlan-interface10] quit
    [SwitchA] interface vlan-interface 11
    [SwitchA-Vlan-interface11] isis ipv6 enable 1
    [SwitchA-Vlan-interface11] quit
    

    # Configure Switch B.

    <SwitchB> 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] address-family ipv6
    [SwitchB-isis-1-ipv6] quit
    [SwitchB-isis-1] quit
    [SwitchB] interface vlan-interface 10
    [SwitchB-Vlan-interface10] isis ipv6 enable 1
    [SwitchB-Vlan-interface10] quit
    [SwitchB] interface vlan-interface 13
    [SwitchB-Vlan-interface13] isis ipv6 enable 1
    [SwitchB-Vlan-interface13] quit
    

    # Configure Switch C.

    <SwitchC> system-view
    [SwitchC] isis 1
    [SwitchC-isis-1] network-entity 10.0000.0000.0003.00
    [SwitchC-isis-1] address-family ipv6
    [SwitchC-isis-1-ipv6] quit
    [SwitchC-isis-1] quit
    [SwitchC] interface vlan-interface 11
    [SwitchC-Vlan-interface11] isis ipv6 enable 1
    [SwitchC-Vlan-interface11] quit
    [SwitchC] interface vlan-interface 13
    [SwitchC-Vlan-interface13] isis ipv6 enable 1
    [SwitchC-Vlan-interface13] quit
    
  3. Configure BFD functions:

    # Enable BFD and configure BFD parameters on Switch A.

    [SwitchA] bfd session init-mode active
    [SwitchA] interface vlan-interface 10
    [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.

    [SwitchB] bfd session init-mode active
    [SwitchB] interface vlan-interface 10
    [SwitchB-Vlan-interface10] isis ipv6 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 BFD session information on Switch A.

<SwitchA> display bfd session

 Total Session Num: 1            Init Mode: Active

 IPv6 Session Working Under Ctrl Mode:

     Local Discr: 1441                Remote Discr: 1450
       Source IP: FE80::20F:FF:FE00:1202 (link-local address of Vlan-interface10 on Switch A)
  Destination IP: FE80::20F:FF:FE00:1200 (link-local address of Vlan-interface10 on Switch B)
   Session State: Up                     Interface: Vlan10
       Hold Time: 2319ms

# Display routes destined for 2001:4::0/64 on Switch A.

<SwitchA> display ipv6 routing-table 2001:4::0 64

Summary Count : 1

Destination: 2001:4::/64                                 Protocol  : IS_L1
NextHop    : FE80::20F:FF:FE00:1200                      Preference: 15
Interface  : Vlan10                                      Cost      : 10

The output shows that Switch A and Switch B communicate through VLAN-interface 10. Then the link over VLAN-interface 10 fails.

# Display routes destined for 2001:4::0/64 on Switch A.

<SwitchA> display ipv6 routing-table 2001:4::0 64

Summary Count : 1

Destination: 2001:4::/64                                 Protocol  : IS_L1
NextHop    : FE80::BAAF:67FF:FE27:DCD0                   Preference: 15
Interface  : Vlan11                                      Cost      : 20

The output shows that Switch A and Switch B communicate through VLAN-interface 11.