Avaya Media Gateway G250, Administration Manual

Page: 543 / 840

Configuring VRRP
Issue 5 June 2008 543
The concept underlying VRRP is that a router can back up other routers, in addition to
performing its primary routing functions. This redundancy is achieved by introducing the
concept of a virtual router. A virtual router is a routing entity associated with multiple physical
routers. One of the physical routers with which the virtual router is associated performs the
routing functions. This router is known as the master router. For each virtual router, VRRP
selects a master router. If the selected master router fails, another router is selected as master
router.
In VRRP, two or more physical routers can be associated with a virtual router, thus achieving
extreme reliability. In a VRRP environment, host stations interact with the virtual router. The
stations are not aware that this router is a virtual router, and are not affected when a new router
takes over the role of master router. Thus, VRRP is fully interoperable with any host station.
You can activate VRRP on an interface using a single command while allowing for the
necessary fine-tuning of the many VRRP parameters. For a detailed description of VRRP, see
VRRP standards and published literature.
VRRP configuration example
Figure 38 illustrates an example of a VRRP configuration:
Figure 38: VRRP configuration example