H3C Technologies H3C MSR 5600 - Manual (Page 75)

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Configuring BFD for a VRRP backup to monitor the master
Network requirements
As shown in Figure 17 , Router A and Router B belong to VRRP group 1, whose virtual IP address is
192.168.0.10.
The default gateway of the hosts in the LAN is 192.168.0.10. When Router A works correctly, the hosts in
the LAN access the external network through Router A. When Router A fails, the hosts in the LAN access
the external network through Router B.
If the master in a VRRP group fails and BFD is not configured, the backup cannot become the master until
the configured timeout timer expires. The timeout is usually 3 to 4 seconds, which is a long delay for most
applications. To solve this problem, VRRP uses BFD to probe the state of the master. Once the master fails,
the backup can become the new master in milliseconds.
Figure 17 Network diagram
Configuration procedure
1. Configure VRRP on Router A:
system-view
[RouterA] interface ethernet 1/1
# Create VRRP group 1, and configure the virtual IP address 192.168.0.10 for the group. Set the
priority of Router A in VRRP group 1 to 110.
[RouterA-Ethernet1/1] vrrp vrid 1 virtual-ip 192.168.0.10
[RouterA-Ethernet1/1] vrrp vrid 1 priority 110
[RouterA-Ethernet1/1] return
2. Configure BFD on Router B: