Configuring VRRP 1021
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Configuring VRRP
This chapter describes how to configure Virtual Routing Redundancy 
Protocol (VRRP) on the switch. VRRP can help create redundancy on 
networks in which end-stations are statically configured with the default 
gateway IP address.
The topics covered in this chapter include:
• VRRP Overview
• Default VRRP Values
• Configuring VRRP Features (Web)
• Configuring VRRP Features (CLI)
• VRRP Configuration Example
VRRP Overview
The Virtual Router Redundancy (VRRP) protocol is designed to handle 
default router (L3 switch) failures by providing a scheme to dynamically elect 
a backup router. VRRP can help minimize black hole periods due to the 
failure of the default gateway router during which all traffic directed towards 
it is lost until the failure is detected. 
How Does VRRP Work?
VRRP eliminates the single point of failure associated with static default 
routes by enabling a backup router to take over from a master router without 
affecting the end stations using the route. The end stations will use a virtual 
IP address that will be recognized by the backup router if the master router 
fails. Participating routers use an election protocol to determine which router 
is the master router at any given time. A given port may appear as more than 
one virtual router to the network, also, more than one port on a switch may be 
configured as a virtual router. Either a physical port or a routed VLAN may 
participate.