Vyatta Network OS Documentation

Learn how to install, configure and operate the Vyatta NOS, which helps drive our virtual networking & physical platforms portfolio.

VRRP synchronization group

Interfaces in a VRRP synchronization group (“sync group”) are synchronized such that, if one of the interfaces in the group fails over to backup, all interfaces in the group fail over to backup. For example, in many cases, if one interface on a master router fails, the whole router fails over to a backup router. By assigning all the interfaces in a set of VRRP routers to a sync group, the failure of one interface triggers a failover of all the interfaces in the sync group to the backups that are configured for each interface in the sync group.

If you manually disable an interface that belongs in a VRRP sync group, whether the group is acting as the master or backup router, the state of the VRRP Finite State Machine (FSM) for each of the interfaces within the group changes to the fault state. A transition to the fault state is triggered by one of the following reasons:

  • An interface has been administratively shut down.
  • A media link failure has been detected.
  • An interface hardware failure has been detected.

If the interfaces in the fault state remain in this state because they are not enabled, these interfaces remain in the fault state, thereby, terminating the router failover services that are available through the VRRP feature. For VRRP to function, you must have both master and backup VRRP routers.

Note: If you have to disable an interface that belongs to a VRRP sync group, first create a new sync group that consists of the given interface and the other interface that is paired with it (master or backup) by using the interfaces interface vrrp vrrp-group group-id sync-group group command. With this step, you are essentially moving the set of interfaces to a new sync group when you create a new sync group because interfaces can belong only to one sync group at any given time. After creating the new sync group, you can proceed with the disabling of the given interface without terminating the router failover services on the sync group in which the interface initially resided.
Note: The configuration of a sync group does not take effect or is not reflected in the active state of VRRP until there is more than one group in the sync group.