Reference Guide

Virtual Router Redundancy Protocol (VRRP) | 1029
VRRP Benefits
With VRRP configured 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 they are not dependent on IGP
protocols to converge or update routing tables.
VRRP Implementation
E-Series supports an unlimited total number of VRRP groups on the switch while supporting up to 255
VRRP groups on a single interface (Table 54-106).
C-Series supports a total of 128 VRRP groups on the switch with varying number of maximum VRRP
groups per interface (Table 54-106).
S25/S50 supports a total of 120 VRRP groups on a switch with FTOS or a total of 20 VRRP groups when
using SFTOS. The S-Series supports varying number of maximum VRRP groups per interface
(Table 54-106).
The S4810 supports a total of 2000 VRRP groups on a switch and 512 VRRP groups per interface
(Table 54-107).
The S55 and S60 support a total of 2000 VRRP groups on a switch and up to 100 VRRP groups per
interface (Table 54-107).
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.
Though FTOS on E-Series supports unlimited VRRP groups, 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 E-Series, the CP on the C-Series, S4810,
S55, and S60, or the FP on the S25/S50. To avoid throttling VRRP advertisement packets, Dell Force10
recommends you to increase the VRRP advertisement interval to a value higher than the default value of 1
second. The recommendations are as follows:
Table 54-106. Recommended VRRP Advertise Intervals
Total VRRP Groups
Recommended Advertise Interval Groups/Interface
E-Series C-Series
S-Series
(S25, S50)
E-Series
ExaScale
E-Series
TeraScale C-Series
S-Series
(S25, S50)
Less than 250 1 second 1 second 1 second 512 255 12 12
Between 250 and 450 2 seconds 2 - 3 seconds 2 - 3 seconds 512 255 24 24
Between 450 and 600 3 seconds 4 seconds 3 - 4 seconds 512 255 36 36
Between 600 and 800 4 seconds 5 seconds 4 seconds 512 255 48 48
Between 800 and 1000 5 seconds 5 seconds 5 seconds 512 255 84 84