VRRP is configured on a per-interface basis from within
mode. To define a new VR address, use
ip vrrp-virtual-router <vrid> for
ipv6 vrrp-virtual-router <vrid> for IPv6 when configuring an
<vrid> must be an integer from
1-255. This identifier must be
identical for all nodes in the same cluster using a specific VR address. The VR
ID must also be different from VR IDs used for other VR addresses on any other
VRRP router on the network segment connected to this interface.
The VR ID must only be unique on a single layer 2 network segment. The same VR ID may be used on different segments.
In situations where it is unclear whether or not there is other VRRP traffic on a segment, run packet captures looking for VRRP to see if any turns up. There would typically be at least one VRRP advertisement per second from other nodes on the network. A packet capture would also show which VR IDs are active on the segment and thus should be avoided.
Though it is common to use the last octet of the VR address as the VR ID, this is not required.
Example which creates a new virtual router address:
tnsr(config)# int TenGigabitEthernet6/0/0 tnsr(config-interface)# ip vrrp-virtual-router 220 tnsr(config-vrrp4)#
This command enters
config-vrrp4 (IPv4) or
config-vrrp6 (IPv6) mode to
configure the properties of the VR address. This mode includes the following
- virtual-address <ip-address>
The IPv4 or IPv6 address which will be shared by the virtual router. Also referred to as the “Virtual Router Address” or “VR Address”.
For the primary node, or owner, for this address (priority
255), the same IP address must be configured on an interface.
- accept-mode (true|false)
Controls whether TNSR will accept packets delivered to this virtual address while in master state if it is not the IP address owner. The default is ‘false’.
Deployments that rely on pinging the virtual address or using it for services such as DNS or IPsec should enable this feature.
IPv6 Neighbor Solicitations and Neighbor Advertisements MUST NOT be dropped when accept-mode is ‘false’.
- preempt (true|false)
Instructs TNSR whether or not to preempt a lower priority peer to become master. The default value is
true, and the owner of a VR address will always preempt other nodes, no matter how this value is set. When set to
false, a failed node will not take back over from the current mater when it recovers, but would wait until a new election occurs.
- priority <priority>
The priority for the VR address on this host. Higher values are preferred during the master election process, with the highest priority router currently operating winning the election.
The primary node, which is the owner of the VR address, must use a priority of
255and no other node should have that priority. Lower priority nodes should use unique priority values, evenly distributed throughout the
1-254range, depending on the number of nodes. The default value is
- v3-advertisement-interval <interval>
The interval, specified in centiseconds (hundredths of a second), at which VRRP advertisements will be sent by this node. The default value is
100, or one second. The value may be in the range of