Advanced Configuration and Management Guide

goes down, the software changes the VRRPE interface’s priority to 40. If another tracked interface goes down, the software reduces the VRID’s priority again, by the amount of the tracked interface’s track priority.

The default track priority for a VRRP Owner is 2. The default track priority for Backups is 1.

You enter the track priority as a parameter with the owner or backup command. See “Track Port” on page 12-17.

Syntax: owner [track-priority <value>]

Syntax: backup [priority <value>] [track-priority <value>]

The syntax is the same for VRRP and VRRPE.

Backup Preempt

By default, a Backup that has a higher priority than another Backup that has become the Master can preempt the Master, and take over the role of Master. If you want to prevent this behavior, disable preemption.

Preemption applies only to Backups and takes effect only when the Master has failed and a Backup has assumed ownership of the VRID. The feature prevents a Backup with a higher priority from taking over as Master from another Backup that has a lower priority but has already become the Master of the VRID.

Preemption is especially useful for preventing flapping in situations where there are multiple Backups and a Backup with a lower priority than another Backup has assumed ownership, because the Backup with the higher priority was unavailable when ownership changed.

If you enable the non-preempt mode (thus disabling the preemption feature) on all the Backups, the Backup that becomes the Master following the disappearance of the Master continues to be the Master. The new Master is not preempted.

NOTE: In VRRP, regardless of the setting for the preempt parameter, the Owner always becomes the Master again when it comes back online.

USING THE CLI

To disable preemption on a Backup, enter commands such as the following:

Router1(config)# inter e 1/6

Router1(config-if-1/6)# ip vrrp vrid 1

Router1(config-if-1/6-vrid-1)# non-preempt-mode

Syntax: non-preempt-mode

The syntax is the same for VRRP and VRRPE.

Forcing a Master Router To Abdicate to a Standby Router

You can force a VRRP Master to abdicate (give away control) of a VRID to a Backup by temporarily changing the Master’s priority to a value less than the Backup’s.

The VRRP Owner always has priority 255. You can even use this feature to temporarily change the Owner’s priority to a value from 1 – 254.

NOTE: When you change a VRRP Owner’s priority, the change takes effect only for the current power cycle. The change is not saved to the startup-config file when you save the configuration and is not retained across a reload or reboot. Following a reload or reboot, the VRRP Owner again has priority 255.

To temporarily change the Master’s priority, use the following CLI method.

USING THE CLI

To change the Master’s priority, enter commands such as the following:

HP9300(config)# ip int eth 1/6

HP9300(config-if-1/6)# ip vrrp vrid 1

HP9300(config-if-1/6-vrid-1)# owner priority 99

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