Dell S4820T Configuration Manual page 1077

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
configured priority on the VRRP group. If the VRRP group is configured 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:
• For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port
information.
• For a port channel interface, enter the keywords port-channel then a number.
– For the S-Series, the valid port channel numbers are from 1 to 128.
• For a VLAN interface, enter the keyword vlan then a number from 1 to 4094.
For a virtual group, you can also track the status of a configured object (the track object-id
command) by entering its object number.
NOTE: You can configure 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 defined and determined to be down.
In addition, if you configure a VRRP group on an interface that belongs to a VRF instance and later
configure object tracking on an interface for the VRRP group, the tracked interface must belong to the
VRF instance.
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 configured 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 configuration 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 configuration 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
Virtual Router Redundancy Protocol (VRRP)
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