3com 4200G ユーザーズマニュアル

Virtual Router Redundancy Protocol (VRRP) is an error-tolerant protocol defined in 
RFC 2338. In LANs with multicast or broadcast capabilities (such as Ethernet), 
VRRP can avoid single point failure through establishing backup links without 
modifying the configuration of dynamic routing protocols and router discovery 
protocols.

You can add two or more switches into a single VRRP group, which can provide 
two or more reliable links to the outside networks, therefore avoiding 
communication interruption resulting from single- or multi- point failure.

Figure 49   Network diagram for VRRP

 

Host A accesses Host B on the Internet, with the VRRP group consisting of Switch 
A and Switch B as its default gateway.

VRRP group settings:

■

VRRP group number: 1

■

Virtual router IP address of the VRRP group: 202.38.160.111.

■

Switch A acts as the master.

■

Switch B acts as the backup, and works in the preemptive mode.

LSW A

Host A

Internet

Host B

LSW B

Vlan- int3

10 .100 .10 .2/24

Virtual IP address 

202.38.160.111 /24

Vlan -int2

202.38.160.1/24

Vlan-int2

202 .38.160 .2/24

202.38.160.3/24

10.2.3 .1/24