3com S7906E 설치 설명서

 

1-11 

     Master IP      : 10.1.1.2 

The output information indicates that when there is a fault on the link between Switch A and Switch C, 

the priority of Switch A decreases to 80. Switch A becomes the backup, and Switch B becomes the 

master. Packets from Host A to Host B are forwarded through Switch B. 

z 

As shown in 

, Switch A and Switch B belong to VRRP group 1, the virtual IP address of 

which is 192.168.0.10. 

z 

The default gateway of the hosts in the LAN is 192.168.0.10. When Switch A works normally, the 

hosts in the LAN access the external network through Switch A. When Switch A fails, the hosts in 

the LAN access the external network through Switch B. 

z 

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 1 second. 

Figure 1-3 Network diagram for monitoring the master on the backup 

Internet

Virtual IP address:

192.168.0.10

Vlan-int2

192.168.0.101/24

Vlan-int2
192.168.0.102/24

Switch A

Switch B

L2 switch

VRRP packets

BFD probe packets

 

 

1)  Configure VRRP on Switch A 

<SwitchA> system-view 

[SwitchA] interface vlan-interface 2 

# Create VRRP group 1, and configure the virtual IP address 192.168.0.10 for the group. Set the priority 

of Switch A in VRRP group 1 to 110. 

[SwitchA-Vlan-interface2] vrrp vrid 1 virtual-ip 192.168.0.10