HP VPN Firewall Appliances High Availability Configuration Guide

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When the master fails, the backup immediately takes over to maintain normal communication.
For more information about track entries, see "Configuring Track."
VRRP application (taking IPv4-based VRRP for example)
1. Master/backup
In master/backup mode, only the master forwards packets. When the master fails, a new master
is elected from the backups. This mode requires only one VRRP group, in which each router holds
a different priority and the one with the highest priority becomes the master.
Figure 5 VRRP in master/backup mode
Assume that Router A is acting as the master to forward packets to external networks, and Router
B and Router C are backups in listening state. When Router A fails, Router B and Router C elect a
new master to forward packets for hosts on the LAN.
2. 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.