Users Guide

Figure 136. Basic VRRP Conguration
VRRP Benets
With VRRP congured on a network, end-station connectivity to the network is not subject to a single point-of-failure. End-station
connections to the network are redundant and are not dependent on internal gateway protocol (IGP) protocols to converge or
update routing tables.
VRRP Implementation
Within a single VRRP group, up to 12 virtual IP addresses are supported.
Virtual IP addresses can belong to the primary or secondary IP address’ subnet congured on the interface. You can ping all the
virtual IP addresses congured on the Master VRRP router from anywhere in the local subnet.
The S4820T supports varying number of maximum VRRP groups per interface. The S4820T supports a total of 2000 VRRP groups
on a switch and 512 VRRP groups per interface.
The following recommendations shown may vary depending on various factors like address resolution protocol (ARP) broadcasts, IP
broadcasts, or spanning tree protocol (STP) before changing the advertisement interval. When the number of packets processed by
RP2/CP/FP processor increases or decreases based on the dynamics of the network, the advertisement intervals may increase or
decrease accordingly.
CAUTION: Increasing the advertisement interval increases the VRRP Master dead interval, resulting in an increased
failover time for Master/Backup election. Take caution when increasing the advertisement interval, as the increased dead
interval may cause packets to be dropped during that switch-over time.
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Virtual Router Redundancy Protocol (VRRP)