VRRP

Virtual Router Redundancy Protocol (VRRP) protection can be provided for the primary as well as for the secondary IP addresses of a VLAN. For multinetting, the IP address assigned to an VRRP virtual router identifier (VRID) can be either the primary or the secondary IP addresses of the corresponding VLAN.

For example, assume a VLAN v1 with two IP addresses: a primary IP address of 10.0.0.1/24, and a secondary IP address of 20.0.0.1/24.

To provide VRRP protection to such a VLAN, you must configure one of the following:
  • Configure VRRP in VLAN v1 with two VRRP VRIDs. One VRID should have the virtual IP address 10.0.0.1/24, and the other VRID should have the virtual IP address 20.0.0.1/24. The other VRRP router, the one configured to act as backup, should be configured similarly.

—OR—
  • Configure VRRP in VLAN v1 with two VRRP VRIDs. One VRID should have the virtual IP address as 10.0.0.1/24, and the other VRID should have the virtual IP address as 20.0.0.1/24.

It is possible for a VRRP VR to have additional virtual IP addresses assigned to it.

In this case, the following conditions must be met:
  • Multiple virtual IP addresses for the same VRID must be on the same subnet.

  • Multiple virtual IP addresses must all not be owned by the switch.

Assuming a VLAN v1 that has IP addresses 1.1.1.1/24 and 2.2.2.2/24, here are some more examples of valid configurations:
  • VRRP VR on v1 with VRID of 99 with virtual IP addresses of 1.1.1.2 and 1.1.1.3
  • VRRP VR on v1 with VRID of 100 with virtual IP addresses of 2.2.2.3 and 2.2.2.4
  • VRRP VR on v1 with VRID of 99 with virtual IP addresses of 1.1.1.98 and 1.1.1.99
  • VRRP VR on v1 with VRID of 100 with virtual IP addresses of 2.2.2.98 and 2.2.2.99
Given the same VLAN v1 as above, here are some invalid configurations:
  • VRRP VR on v1 with VRID of 99 with virtual IP addresses of 1.1.1.1 and 2.2.2.2 (the virtual IP addresses are not on the same subnet)
  • VRRP VR on v1 with VRID of 100 with virtual IP addresses of 2.2.2.2 and 1.1.1.1 (the virtual IP addresses are not on the same subnet)
  • VRRP VR on v1 with VRID of 99 with virtual IP addresses of 1.1.1.1 and 1.1.1.99 (one virtual IP address is owned by the switch and one is not)
  • VRRP VR on v1 with VRID of 100 with virtual IP addresses of 2.2.2.2 and 2.2.2.99 (one virtual IP address is owned by the switch and one is not).