Dell Force10 S4820T S4820T Configuration Guide - Page 1045

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 54-1). C-Series supports a total of 128 VRRP groups on the switch with varying number of maximum VRRP groups per interface (Table 54-1). 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 54-1). The S4810 and S4820T support a total of 2000 VRRP groups on a switch and 512 VRRP groups per interface (Table 54-2). The S55 and S60 support a total of 2000 VRRP groups on a switch and up to 100 VRRP groups per interface (Table 54-2). 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, S4820T, 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 54-1. Recommended VRRP Advertise Intervals Total VRRP Groups Less than 250 Between 250 and 450 Between 450 and 600 Between 600 and 800 Between 800 and 1000 Recommended Advertise Interval Groups/Interface E-Series C-Series S-Series (S25, S50) E-Series E-Series S-Series ExaScale TeraScale C-Series (S25, S50) 1 second 1 second 1 second 512 255 12 12 2 seconds 2 - 3 seconds 2 - 3 seconds 512 255 24 24 3 seconds 4 seconds 3 - 4 seconds 512 255 36 36 4 seconds 5 seconds 4 seconds 512 255 48 48 5 seconds 5 seconds 5 seconds 512 255 84 84 Virtual Router Redundancy Protocol (VRRP) | 1045