Administrator Guide

The lowered priority of the VRRP group may trigger an election. As the Master/Backup VRRP routers are selected based on the
VRRP group’s priority, tracking features ensure that the best VRRP router is the Master for that group. The sum of all the costs of all
the tracked interfaces must be less than the congured priority on the VRRP group. If the VRRP group is congured as Owner
router (priority 255), tracking for that group is disabled, irrespective of the state of the tracked interfaces. The priority of the owner
group always remains at 255.
For a virtual group, you can track the line-protocol state or the routing status of any of the following interfaces with the interface
interface parameter:
• 40 Gigabit Ethernet: enter fortygigabitethernet slot/port in the track interface command (shown in the following
example).
• 10 Gigabit Ethernet: enter tengigabitethernet slot/port.
• Port channel: enter port-channel number.
• VLAN: enter vlan vlan-id where valid VLAN IDs are from 1 to 4094.
For a virtual group, you can also track the status of a congured object (the track object-id command) by entering its object
number.
NOTE: You can congure a tracked object for a VRRP group (using the track object-id command in INTERFACE-
VRID mode) before you actually create the tracked object (using a track object-id command in CONFIGURATION
mode). However, no changes in the VRRP group’s priority occur until the tracked object is dened and determined to be
down.
Tracking an Interface
To track an interface, use the following commands.
NOTE: The sum of all the costs for all tracked interfaces must be less than the congured priority of the VRRP group.
• Monitor an interface and, optionally, set a value to be subtracted from the interface’s VRRP group priority.
INTERFACE-VRID mode
track interface [priority-cost cost]
The cost range is from 1 to 254.
The default is 10.
• (Optional) Display the conguration and the UP or DOWN state of tracked objects, including the client (VRRP group) that is
tracking an object’s state.
EXEC mode or EXEC Privilege mode
show track
• (Optional) Display the conguration and the UP or DOWN state of tracked interfaces and objects in VRRP groups, including the
time since the last change in an object’s state.
EXEC mode or EXEC Privilege mode
show vrrp
• (Optional) Display the conguration of tracked objects in VRRP groups on a specied interface.
EXEC mode or EXEC Privilege mode
show running-config interface interface
878
Virtual Router Redundancy Protocol (VRRP)