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Configuring VRRP Groups
To configure VRRP, select an interface on one router in the group to serve
as the master virtual router. This physical interface is used as the virtual
address for the router group. Now set the same virtual address and a
priority on the backup routers, and configure an authentication string. You
can also enable the preempt feature which allows a router to take over as
the master router when it comes on line.
Command Usage
Address Assignment –
• The IP address assigned to the virtual router must already be
configured on the router that will be the Owner. In other words, the
IP address for the virtual router exists on one, and only one, router in
the virtual router group, and the network mask for the virtual router
address is derived from the Owner. The Owner will also assume the
role of the Master virtual router in the group.
• If you have multiple secondary addresses configured on the current
VLAN interface, you can add any of these addresses to the virtual
router group.
• The interfaces of all routers participating in a virtual router group must
be within the same IP subnet.
• VRRP creates a virtual MAC address for the master router based on a
standard prefix, with the last octet equal to the group ID. When a
backup router takes over as the master, it continues to forward traffic
addressed to this virtual MAC address. However, the backup router
cannot reply to ICMP pings sent to addresses associated with the
virtual group because the IP address owner is off line.
Virtual Router Priority –
• The Owner of the virtual IP address is automatically assigned the
highest possible virtual router priority of 255. The backup router with
the highest priority will become the master router if the current master