VRRP tracking
To enable VRRP tracking, configure the routers in the VRRP group to operate in preemptive mode first, so that only the router with the highest priority operates as the master for packet forwarding. For more information about track entries, see High Availability Configuration Guide.
The VRRP tracking function uses network quality analyzer (NQA) or bidirectional forwarding detection (BFD) to monitor the state of the master, and establishes the collaboration between the VRRP device state and NQA or BFD through the track function. It implements the following:
Monitors the upstream link and changes the priority of the router according to the state of the link. If the upstream link fails, the hosts on the subnet cannot access external networks through the router and the state of the track entry becomes Negative. The priority of the master decreases by a specified value. Then, a router with a higher priority in the VRRP group becomes the master to maintain the proper communication between the hosts on the subnet and external networks.
Monitors the state of the master on the backups. When the master fails, a backup immediately takes over as the master to ensure uninterrupted communication.
When the track entry changes from Negative to Positive or Notready, the router automatically restores its priority. For more information about track entries, see "Configuring Track."