H3C Technologies H3C SecPath F1000-E - Manual (Page 297)

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VRID : 1 Adver Timer : 5
Admin Status : Up State : Backup
Config Pri : 110 Running Pri : 80
Preempt Mode : Yes Delay Time : 5
Auth Type : Simple Key : hello
Virtual IP : 10.1.1.10
Master IP : 10.1.1.2
VRRP Track Information:
Track Object : 1 State : Negative Pri Reduced : 30
# Display detailed information about VRRP group 1 on Device B when there is a fault on the link between
Device A and Device C.
[DeviceB-GigabitEthernet0/1] display vrrp verbose
IPv4 Standby Information:
Run Mode : Standard
Run Method : Virtual MAC
Total number of virtual routers : 1
Interface GigabitEthernet0/1
VRID : 1 Adver Timer : 5
Admin Status : Up State : Master
Config Pri : 100 Running Pri : 100
Preempt Mode : Yes Delay Time : 5
Auth Type : Simple Key : hello
Virtual IP : 10.1.1.10
Virtual MAC : 0000-5e00-0101
Master IP : 10.1.1.2
The output information shows that when there is a fault on the link between Device A and Device C, the
priority of Device A decreases to 80. Device A becomes the backup, and Device B becomes the master.
Packets from Host A to Host B are forwarded through Device B.
Configuring BFD for a VRRP Backup to Monitor the Master
Network requirements
• As shown in Figure 3 , Device A and Device 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 Device A works normally, the
hosts in the LAN access the external network through Device A. When Device A fails, the hosts in
the LAN access the external network through Device B.
• If BFD is not configured, when the master in a VRRP group fails, the backup cannot become the
master until the configured timeout timer expires. The timeout is generally three to four seconds and
therefore the switchover is slow. 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 within 100 milliseconds.