116Load sharingYou can create more than one VRRP group on an interface of a router, and allow the router to bethe master of one VRRP group and a backup of another at the same time.In load sharing mode, multiple routers provide services at the same time. This mode requires twoor more VRRP groups, each of which includes a master and one or more backups. The masters ofthe VRRP groups are assumed by different routers, as shown in Figure 27.Figure 27 VRRP in load sharing modeHost AHost BHost CRouter ABackupRouter BBackupRouter CMasterVRRP group 2 VRRP group 3VRRP group 1MasterBackupBackup BackupMasterBackupNetworkA router can be in multiple VRRP groups and hold a different priority in different group.In Figure 27, three VRRP groups are present:• VRRP group 1: Router A is the master; Router B and Router C are the backups.• VRRP group 2: Router B is the master; Router A and Router C are the backups.• VRRP group 3: Router C is the master; Router A and Router B are the backups.For load sharing among Router A, Router B, and Router C, hosts on the LAN need to beconfigured to use VRRP group 1, 2, and 3 as the default gateways respectively. Whenconfiguring VRRP priorities, make sure that each router holds such a priority in each VRRP groupthat it will take the expected role in the group.VRRP load balancing modeOverviewWhen VRRP works in the standard protocol mode, only the master can forward packets and thebackups are in the state of listening. Although you can create multiple VRRP groups to implement
