Multicast and Routing Guide K/KA/KB.15.15

Syntax:
primary-ip-address [ ip-address | lowest ]
NOTE: For IPv4 only. IPv6 does not have a primary-ip-address option; the primary
IP address is the link-local address of the real interface over which the packet is
transmitted.
Specifies the VIP to designate as the source for VRRP advertisements from the VR.
If there is only one VIP configured on the VR, the default setting (lowest) is sufficient.
Where there are multiple VIPs in the same VR and you want to designate an
advertisement source other than the lowest IP Address, use this command.
For an owner VR, the primary IP address must be one of the VIPs configured on the
VR.
For a backup VR, the primary IP address must be in the same subnet as one of the
VIPs configured on the VR. In addition, the primary IP address for a backup VR must
be one of the IP addresses configured on the VLAN on which the VR is configured.
Executed in VRID context.
Default: lowest
NOTE: It is common in VRRP applications to have only one VIP per VR. In such
cases, the protocol uses that address as the source IP address for VRRP
advertisements, and it is not necessary to specify an address.
Configuring preempt mode on VRRP backup routers
This command applies to VRRP backup routers only and is used to minimize network disruption
caused by unnecessary preemption of the master operation among backup routers. It is executed
in VRID context.
Syntax:
[no] preempt-mode
Disables or re-enables preempt mode. In the default mode, a backup router coming
up with a higher priority than another backup that is currently operating as master
will take over the master function.
Using the no form of the command disables this operation, thus preventing the
higher-priority backup from taking over the master operation from a lower-priority
backup.
This command does not prevent an owner router from resuming the master function
after recovering from being unavailable.
Default: Enabled
Enabling or disabling VRRP operation on a VR
Syntax:
[no] enable
Enabling or disabling a VR enables or disables dynamic VRRP operation on that
VR.
Default: Disabled
Configuring preempt mode on VRRP backup routers 255