Dell Force10 E300, Configuration Manual, Page: 1129 / 1262

Virtual Router Redundancy Protocol (VRRP) | 1129
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
On E-Series ExaScale and TeraScale routers, VRRP is implemented as follows:
• When VRF microcode is not loaded, VRRP supports an unlimited total number of VRRP groups on a
router and up to 255 VRRP groups on an interface (see
Table 58-1 ).
• When VRF microcode is loaded (see Load the VRF CAM Profile on page 1115 ), VRRP supports an
unlimited total number of VRRP groups on a router and up to 15 VRRP groups on an interface (see
Table 58-1 ).
C-Series supports a total of 128 VRRP groups on the switch with varying number of maximum VRRP
groups per interface (
Table 58-1 ).
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 58-1 ).
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 58-1. Recommended VRRP Advertise Intervals
Total VRRP Groups
Recommended Advertise Interval Groups/Interface
E-Series C-Series S-Series
E-Series
ExaScale
E-Series
TeraScale C-Series S-Series
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