Chapter 24: Vrrp; Overview - Cisco SF500-24 Administration Manual

VRRP

Overview

Cisco 500 Series Stackable Managed Switch Administration Guide
This chapter describes how Virtual Router Redundancy Protocol (VRRP) works
and how to configure virtual routers running VRRP through the WEB GUI. The
Sx500 models do not support the VRRP feature.
It covers the following topics:
• Overview
• Configurable Elements of VRRP
• Configuring VRRP Through Web GUI
• Configuring VRRP Through Web GUI
VRRP is an election and redundancy protocol that dynamically assigns the
responsibility of a virtual router to one of the physical routers on a LAN. This
increase the availability and reliability of routing paths in the network.
In VRRP, one physical router in a virtual router is elected as the master, with the
other physical router of the same virtual router acting as backups in case the
master fails. The physical routers are referred as VRRP routers.
The default gateway of a participating host is assigned to the virtual router instead
of a physical router. If the physical router that is routing packets on behalf of the
virtual router fails, another physical router is selected to automatically replace it.
The physical router that is forwarding packets at any given time is called the
master router.
VRRP also enables load sharing of traffic. Traffic can be shared equitably among
available routers by configuring VRRP in such a way that traffic to and from LAN
clients are shared by multiple routers.
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