Virtual IP
Virtual MAC
Master IP
The output shows that when a fault is on the link between Router A and Router C, the priority of Router
A decreases to 80. Router A becomes the backup, and Router B becomes the master. Packets from Host
A to Host B are forwarded through Router B.
Configuring BFD for a VRRP backup to monitor the master
Network requirements
As shown in
•
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:
<RouterA> system-view
[RouterA] interface gigabitethernet 1/0
: 10.1.1.10
: 0000-5e00-0101
: 10.1.1.2
Figure
17, Router A and Router B belong to VRRP group 1, whose virtual IP address is
66