H3C Technologies H3C S7500E Series Switches - Manual (Page 141)

10-8
Figure 10-5 VRRP in master/backup mode
Assume that 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 to forward packets to hosts on the LAN.
Load sharing
More than one VRRP group can be created on an interface of a router to allow the router to be
the master of one VRRP group but a backup of another at the same time.
In load sharing mode, multiple routers provide services simultaneously. This mode requires two
or more VRRP groups, each of which comprises a master and one or more backups. The
masters of the VRRP groups are assumed by different routers, as shown in Figure 10-6 .
Figure 10-6 VRRP in load sharing mode
Host A
Host B
Host C
Router A
Backup
Router B
Backup
Router C
Master
VRRP group 2 VRRP group 3 VRRP group 1
Master
Backup
Backup Backup
Master
Backup
Network
A router can be in multiple VRRP groups and hold a different priority in a different group.