Within a VRRP VLAN, one link can go down while the remaining links in the VLAN remain operational. Because the VRRP VLAN continues to function, a virtual router associated with that VLAN does not register a master router failure.
Note
In this context, local implies an address from the same VRF as the IP interface where VRRP is being configured.
The critical IP address resolves this issue. If the critical IP address fails, it triggers a failover of the master router.
You can specify the local router IP interface uplink from the VRRP router to the network as the critical IP address. This ensures that, if the local uplink interface fails, VRRP initiates a master router failover to one of the backup routers.
In VRRP, the local network uplink interface on router 1 is shown as the critical IP address for router 1. As well, the same network uplink is shown as the critical IP address for router 2. Router 2 also requires a critical IP address for cases in which it assumes the role of the master router.
With the support of VRRP and the critical IP interface linked to VRRP, you can build reliable small core networks that provide support for converged applications, such as voice and multimedia.
Note
A Brouter port with a VLACP critical IP address in a VRRP is supported.