Dell Force10 Z9000 FTOS Configuration Guide for Z9000 System - Page 951

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 router while supporting up to 255 VRRP groups on a single interface (Table 49-1). C-Series supports a total of 128 VRRP groups on the switch with varying number of maximum VRRP groups per interface (Table 49-1). S-Series 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 49-1). Z-Series supports a total of 255 VRRP groups on a switch. The total number of VRRP groups per system should be less than 512. Note: The Layer 2 CAM is limited to 512 Local Destination Addresses, which limits the number of VRRP groups that can be supported. This number may be further reduced depending on the number of Layer 3 VLANs configured in the system as the Layer 3 VLANs also use Local Destination Addresses. 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, or the FP on the S-Series. 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 49-1. Recommended VRRP Advertise Intervals Total VRRP Groups Less than 250 Between 250 and 450 Recommended Advertise Interval Groups/Interface E-Series E-Series E-Series C-Series S-Series Z-Series ExaScale TeraScale C-Series S-Series Z-Series 1 second 1 second 1 second 1 second 512 255 12 12 12 2 seconds 2 - 3 seconds 2 - 3 seconds 2 - 3 512 255 24 24 24 seconds Virtual Router Redundancy Protocol (VRRP) | 951