Advanced Configuration and Management Guide

NOTE: You cannot set the priority of a VRRP Owner. The Owner’s priority is always 255.

VRRPE Syntax

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

The software requires you to identify a VRRPE interface as a Backup for its VRID before you can activate the interface for the VRID. However, after you configure the VRID, you can use this command to change its priority or track priority. The parameter values are the same as for VRRP.

Suppression of RIP Advertisements on Backup Routers for the Backup Up Interface

Normally, a VRRP or VRRPE Backup includes route information for the virtual IP address (the backed up interface) in RIP advertisements. As a result, other routers receive multiple paths for the backed up interface and might sometimes unsuccessfully use the path to the Backup rather than the path to the Master.

You can prevent the Backups from advertising route information for the backed up interface by enabling suppression of the advertisements.

USING THE CLI

To suppress RIP advertisements for the backed up interface in Router2, enter the following commands:

Router2(config)# router rip

Router2(config-rip-router)# use-vrrp-path

Syntax: use-vrrp-path

The syntax is the same for VRRP and VRRPE.

Hello Interval

The Master periodically sends Hello messages to the Backups. The Backups use the Hello messages as verification that the Master is still on-line. If the Backup routers stop receiving the Hello messages for the period of time specified by the Dead interval, the Backup routers determine that the Master router is dead. At this point, the Backup router with the highest priority becomes the new Master router. The Hello interval can be from 1 – 84 seconds. The default is 1 second.

NOTE: The default Dead interval is three times the Hello Interval plus one-half second. Generally, if you change the Hello interval, you also should change the Dead interval on the Backup routers.

USING THE CLI

To change the Hello interval on the Master to 10 seconds, enter the following commands:

Router1(config)# inter e 1/6

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

Router1(config-if-1/6-vrid-1)# hello-interval 10

Syntax: hello-interval <value>

The syntax is the same for VRRP and VRRPE.

Dead Interval

The Dead interval is the number of seconds a Backup waits for a Hello message from the Master before determining that the Master is dead. When Backups determine that the Master is dead, the Backup with the highest priority becomes the new Master. The Dead interval can be from 1 – 84 seconds. The default is 3.5 seconds. This is three times the default Hello interval (1 second) plus one-half second added by the router software. The software automatically adds one-half second to the Dead interval value you enter.

USING THE CLI

To change the Dead interval on a Backup to 30 seconds, enter the following commands:

Router2(config)# inter e 1/5

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