实验内容：

要求PC1 和PC2通过R1-R2-R4这条链路作为主链路进行业务传输。R1-R3-R4这条链路作为备份链路，用户希望当主链路出现故障时，可以快速启用备份链路来承担业务的传输。

实验拓扑：

实验配置(各个接口IP配置已省略)：

[R4]ip route-static 2.2.2.0 24 4.4.4.1 preference 60

[R4]ip route-static 1.1.1.0 24 3.3.3.1 preference 80

[R4]ip route-static 6.6.6.0 24 3.3.3.1

[R4]ip route-static 6.6.6.0 24 4.4.4.1

[R4]bfd

[R4-bfd]quit

[R4]bfd rui bind peer-ip 1.1.1.1

[R4-bfd-session-rui]discriminator local 2

[R4-bfd-session-rui]discriminator remote 1

[R4-bfd-session-rui]commit

[R4-bfd-session-rui]inter g0/0/1

[R4-GigabitEthernet0/0/1]standby track bfd-session session-name rui 开启联动功能并绑定

[R3]ip route-static 5.5.5.0 24 4.4.4.2

[R3]ip route-static 6.6.6.0 24 2.2.2.1

[R2]ip route-static 6.6.6.0 24 1.1.1.1

[R2]ip route-static 5.5.5.0 24 3.3.3.2

[R1]ip route-static 3.3.3.0 24 1.1.1.2 preference 80

[R1]ip route-static 5.5.5.0 24 1.1.1.2

[R1]ip route-static 5.5.5.0 24 2.2.2.2

[R1]ip route-static 4.4.4.0 24 2.2.2.2 preference 60 (优先级值越小优先级越大)

[R1]bfd

[R1-bfd]qui

[R1]bfd cai bind peer-ip 3.3.3.2

[R1-bfd-session-cai]discriminator local 1

[R1-bfd-session-cai]discriminator remote 2

[R1-bfd-session-cai]commit

[R1]inter g0/0/1

[R1-GigabitEthernet0/0/1]standby track bfd-session session-name cai

实验验证：

display bfd session all ：查看BFD会话状态是否为UP

display standby state：查看BFD会话和备份接口的状态信息。

2017-12-23 蔡瑞