H3C Technologies H3C SecPath F1000-E - Manual (Page 835)

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Figure 4 VRRP in master/backup mode
At the beginning, Router A is the master and therefore can forward packets to external networks,
whereas Router B and Router C are backups and are thus in the state of listening. If Router A fails, Router
B and Router C elect for a new master. The new master takes over the forwarding task to provide services
to hosts on the LAN.
Load balancing
You can create more than one VRRP group on an interface of a router, and allow the router to be the
master of one VRRP group but a backup of another at the same time.
In load balancing mode, multiple routers provide services at the same time. This mode requires two or
more VRRP groups, each of which includes a master and one or more backups. The masters of the VRRP
groups can be assumed by different routers, as shown in Figure 5 .
Figure 5 VRRP in load balancing mode
Host A
Host B
Host C
Router A
Backup
Router B
Backup
Router C
Master
Virtual router 2 Virtual router 3 Virtual router 1
Master
Backup
Backup Backup
Master
Backup
Network