Avaya P332G-ML Manual Do Utilizador

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Chapter 12
Avaya P330 Layer 3 Features
106
Avaya P332G-ML User’s Guide
VRRP (Virtual Router Redundancy Protocol) Configuration
VRRP Overview
VRRP is an IETF protocol designed to support redundancy of routers on the LAN, 
as well as load balancing of traffic. VRRP is transparent to host stations, making it 
an ideal choice when redundancy, load balancing and ease of configuration are all 
required.
The concept underlying VRRP is that a router can backup other routers, in addition 
to performing its primary routing functions. This redundancy is achieved by 
introducing a virtual router. A virtual router is a routing entity associated with 
multiple physical routers. The routing functions of the virtual router are performed 
by one of the physical routers with which it is associated. 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. They are not aware that this router is a virtual router, and they are 
not affected when a new router takes over the role of master router. This makes 
VRRP fully interoperable with every host station.
VRRP can be activated 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, refer to VRRP standards and published literature.