Reference Guide

Virtual Router Redundancy Protocol (VRRP) | 989
VRRP Implementation
The S5000 supports a total of 255 VRRP groups on a switch.
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 configured on the interface. You can ping all the virtual IP
addresses configured on the Master VRRP router from anywhere in the local subnet.
Default VRRP settings may affect the maximum number of groups that can be configured and work
efficiently as a result of hardware throttling VRRP advertisement packets reaching the RP2 processor on
the S5000. To avoid throttling VRRP advertisement packets, Dell Networking recommends you to increase
the VRRP advertisement interval to a value higher than the default value of 1 second. The
recommendations are as follows:
The recommendations in Table 56-1 may vary depending on various factors like ARP broadcasts, IP
broadcasts, or 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 in may increase or decrease accordingly.
VRRP Configuration
By default, VRRP is not configured.
Configuration Task List for VRRP
The following list specifies the configuration tasks for VRRP:
Table 56-1. Recommended VRRP Advertise Intervals on the S5000
Total VRRP Groups
Recommended Advertise
Interval
Groups/
Interface
S5000 S5000
Less than 250 1 second 512
Between 250 and 450 2 - 3 seconds 512
Between 450 and 600 3 - 4 seconds 512
Between 600 and 800 4 seconds 512
Between 800 and 1000 5 seconds 512
Between 1000 and 1200 7 seconds 512
Between 1200 and 1500 8 seconds 512
CAUTION: Increasing the advertisement interval increases the VRRP Master dead interval, resulting in an
increased failover time for Master/Backup election. Take extra caution when increasing the advertisement
interval, as the increased dead interval may cause packets to be dropped during that switch-over time.