3Com CoreBuilder 3500, Руководство по внедрению

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Key Concepts 321
The parallel design in Figure 63 takes advantage of the capabilities of
VRRP. This design can be extended to include more routers and more
subnetworks. In a more complex virtual router scheme with many backup
routers, this method ensure that all routers have adequate backup in the
event of a failure.
VRRP provides for this by making you assign each virtual router on the
LAN a priority value between 1 and 255. (255 means that the virtual
router is the actual owner of the IP addresses.) If the Master fails, the
virtual router with the next-highest priority takes over Master
responsibilities until the original Master comes back online.
If two routers have the same priority, VRRP resolves the conflict by
selecting the virtual router with the numerically-highest primary IP
address. In other words, if Virtual Router A (primary IP address of 1.1.1.2)
and Virtual Router C (primary IP address of 1.1.1.3) both have a priority of
100, Virtual Router C would have a higher priority than Virtual Router A.
CAUTION: Configure all of the routers participating in the VRRP scheme
on your network to have the same representation of the network. If some
routers have a different view of the topology than others, a backup
router failure is more likely, with the resultant loss of some or all end
hosts’ connection to the network.