Figure 364 Example: Vrrp, Master Becomes Unavailable; Figure 365 Example: Vrrp, No Preempt - ZyXEL Communications Unified Security Gateway ZyWALL 300 User Manual

Chapter 33 Device HA
Every router in a virtual router must use the same advertisement interval.
If Router A becomes unavailable, it stops sending messages to Router B. Router B detects this
and assumes the role of the master router. This is illustrated below.

Figure 364 Example: VRRP, Master Becomes Unavailable

Router B is now using the IP address of the default gateway, and it is forwarding packets for
the network. The loss of Router A has no effect on the network.
If there is more than one backup router, the backup router with the highest priority becomes
the master router. The other backup routers remain backup routers.
If Router A becomes available again, one of two things can happen, depending on the settings
in Router A.
1 Router A may preempt Router B and become the master router again. In this case, the
network returns to the state shown in
2 Router A returns to the network, but Router B remains the master router. This is
illustrated below.

Figure 365 Example: VRRP, No Preempt

In this case, Router A becomes a backup router, and it uses its Manage IP,
192.168.10.111. Router B remains the master router until it becomes unavailable.
494
Figure 363 on page 493.
ZyWALL USG 300 User's Guide