Avaya ERS 8600 series, Configuration Manual

Page: 64 / 420

Scaling
The Avaya Ethernet Routing Switch 8800/8600 supports 255 VRRP interfaces for each switch.
Critical IP address
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.
As a result, if the local router IP interface connecting the virtual router to the external network
fails, this does not automatically trigger a master router failover.
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 the following figure, the local network uplink interface on R1 is shown as the critical IP
address for R1. As well, the similar network uplink is shown as the critical IP address for R2.
R2 also requires a critical IP address for cases in which it assumes the role of the master router.
Figure 13: VRRP with critical IP
The critical address can be any one of the global unicast IPv6 addresses assigned to any local
IPv6 interfaces.
IPv6 routing fundamentals
64 Configuration — IPv6 Routing November 2010