组网需求

为需要快速检测和监控网络中的IPv6链路，可以创建BFD for IPv6会话。如图1所示，使用BFD异步模式检测DeviceA和DeviceC之间的多跳路径。

图1 BFD for IPv6多跳检测示例组网图

本例中interface1，interface2分别代表100GE1/0/1，100GE1/0/2。

配置思路

操作步骤

1. 配置DeviceA、DeviceB和DeviceC各接口的IPv6地址，并配置设备之间采用OSPFv3协议互连。
   # 配置DeviceA。

   <HUAWEI> system-view
   [~HUAWEI] sysname DeviceA
   [*HUAWEI] commit
   [~DeviceA] ospfv3 1
   [*DeviceA-ospfv3-1] router-id 10.1.1.1
   [*DeviceA-ospfv3-1] area 0
   [*DeviceA-ospfv3-1-area-0.0.0.0] quit
   [*DeviceA-ospfv3-1] quit
   [*DeviceA] commit
   [~DeviceA] interface 100ge 1/0/1
   [~DeviceA-100GE1/0/1] undo portswitch
   [*DeviceA-100GE1/0/1] ipv6 enable
   [*DeviceA-100GE1/0/1] ipv6 address 2001:db8:1::1 64
   [*DeviceA-100GE1/0/1] ospfv3 1 area 0
   [*DeviceA-100GE1/0/1] quit
   [*DeviceA] commit

   # 配置DeviceB。

   <HUAWEI> system-view
   [~HUAWEI] sysname DeviceB
   [*HUAWEI] commit
   [~DeviceB] ospfv3 1
   [*DeviceB-ospfv3-1] router-id 10.1.1.2
   [*DeviceB-ospfv3-1] area 0
   [*DeviceB-ospfv3-1-area-0.0.0.0] quit
   [*DeviceB-ospfv3-1] quit
   [*DeviceB] commit
   [~DeviceB] interface 100ge 1/0/1
   [~DeviceB-100GE1/0/2] undo portswitch
   [*DeviceB-100GE1/0/1] ipv6 enable
   [*DeviceB-100GE1/0/1] ipv6 address 2001:db8:1::2 64
   [*DeviceB-100GE1/0/1] ospfv3 1 area 0
   [*DeviceB-100GE1/0/1] quit
   [*DeviceB] commit
   [~DeviceB] interface 100ge 1/0/2
   [~DeviceB-100GE1/0/2] undo portswitch
   [*DeviceB-100GE1/0/2] ipv6 enable
   [*DeviceB-100GE1/0/2] ipv6 address 2001:db8:2::1 64
   [*DeviceB-100GE1/0/2] ospfv3 1 area 0
   [*DeviceB-100GE1/0/2] quit
   [*DeviceB] commit

   # 配置DeviceC。

   <HUAWEI> system-view
   [~HUAWEI] sysname DeviceC
   [*HUAWEI] commit
   [~DeviceC] ospfv3 1
   [*DeviceC-ospfv3-1] router-id 10.1.1.3
   [*DeviceC-ospfv3-1] area 0
   [*DeviceC-ospfv3-1-area-0.0.0.0] quit
   [*DeviceC-ospfv3-1] quit
   [*DeviceC] commit
   [~DeviceC] interface 100ge 1/0/2
   [~DeviceC-100GE1/0/2] undo portswitch
   [*DeviceC-100GE1/0/2] ipv6 enable
   [*DeviceC-100GE1/0/2] ipv6 address 2001:db8:2::2 64
   [*DeviceC-100GE1/0/2] ospfv3 1 area 0
   [*DeviceC-100GE1/0/2] quit
   [*DeviceC] commit

2. 在DeviceA和DeviceC上使能全局BFD功能，并配置DeviceA和DeviceC之间的多跳路由检测。
   # 配置DeviceA。

   [~DeviceA] bfd
   [*DeviceA-bfd] quit
   [*DeviceA] bfd ipv6session bind peer-ipv6 2001:db8:2::2
   [*DeviceA-bfd-session-ipv6session] discriminator local 1
   [*DeviceA-bfd-session-ipv6session] discriminator remote 2
   [*DeviceA-bfd-session-ipv6session] quit
   [*DeviceA] commit

   # 配置DeviceC。

   [~DeviceC] bfd
   [*DeviceC-bfd] quit
   [*DeviceC] bfd ipv6session bind peer-ipv6 2001:db8:1::1
   [*DeviceC-bfd-session-ipv6session] discriminator local 2
   [*DeviceC-bfd-session-ipv6session] discriminator remote 1
   [*DeviceC-bfd-session-ipv6session] quit
   [*DeviceC] commit

检查配置结果

# 配置完成后，DeviceA和DeviceC之间可以相互Ping通。以DeviceA的显示结果为例。

[~DeviceA] ping ipv6 2001:db8:2::2
PING 2001:db8:2::2 : 56  data bytes, press CTRL_C to break
    Reply from 2001:db8:2::2
    bytes=56 Sequence=1 hop limit=64 time=22 ms
    Reply from 2001:db8:2::2
    bytes=56 Sequence=2 hop limit=64 time=1 ms
    Reply from 2001:db8:2::2
    bytes=56 Sequence=3 hop limit=64 time=1 ms
    Reply from 2001:db8:2::2
    bytes=56 Sequence=4 hop limit=64 time=1 ms

    Reply from 2001:db8:2::2
    bytes=56 Sequence=5 hop limit=64 time=1 ms
  ---2001:db8:2::2 ping statistics---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max=1/5/22 ms

# 在DeviceA和DeviceC上查看BFD会话详细信息。以DeviceA的显示结果为例。

[~DeviceA] display bfd session all verbose
2020-01-01 11:21:06.8
(w): State in WTR 
(*): State is invalid
Total UP/DOWN Session Number : 1/0
--------------------------------------------------------------------------------
  Name : ipv6session                    (Multiple Hops) State : Up                    
------------------------------------------------------------------------------
  Local Discriminator    : 1                Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Peer IP Address
  Bind Session Type      : Static
  Bind Peer IP Address   : 2001:DB8:2::2
  Bind Interface         : -
  FSM Board ID           : 1               TOS-EXP                : 7
  Min Tx Interval (ms)   : 1000      Min Rx Interval (ms)   : 1000
  Actual Tx Interval (ms): 1000             Actual Rx Interval (ms): 1000
  WTR Interval (ms)      : -                Detect Interval (ms)   : 3000
  Local Detect Multi     : 3                Active Multi           : -
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 4784             TTL                    : 254
  Proc Interface Status  : Disable          Process PST            : Disable
  Config PST             : Disable
  Last Local Diagnostic  : No Diagnostic
  Bind Application       : No Application Bind
  Session Description    : - 
------------------------------------------------------------------------------

可以看到建立了一个多跳（Multiple Hops）的BFD会话，状态为UP。