Method of monitoring a member router in a VRRP group

摘要

The invention relates to procedures and methods employed by a backup router in a VRRP group to actively monitor the master router. The backup router monitors the health of the master virtual router by periodically sending traffic through the master router and checking for the correct response. When the master virtual router is determined to be down, then a VRRP status change is triggered by changing the VRRP priority of the monitoring backup virtual router. If the VRRP priority of what was the backup monitoring virtual router becomes greater than the priority of the master virtual router then a status change is triggered so that the master virtual router transitions to being the backup virtual router and the virtual monitoring router becomes the master virtual router. After these transitions have taken place the monitoring router (which is now the master virtual router) continues to attempt to send traffic to what is now a backup virtual router to check if it becomes operational again. When it is determined that this router is up, the monitoring router changes it VRRP priority back to its original priority thus triggering the reverse VRRP state transitions to take place. This method means that a backup virtual router on a VRRP group continually monitors the master virtual router. It will trigger VRRP transitions when it detects that end to end routing on the master virtual router is down so that the master virtual router becomes a backup. When this router comes up, VRRP state changes will again be triggered so that it becomes the master virtual router again.