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Changing the Advertisement Interval
By default, the MASTER router transmits a VRRP advertisement to all members of the VRRP group every one second, indicating
it is operational and is the MASTER router.
If the VRRP group misses three consecutive advertisements, the election process begins and the BACKUP virtual router with
the highest priority transitions to MASTER.
NOTE: To avoid throttling VRRP advertisement packets, Dell Networking recommends increasing the VRRP advertisement
interval to a value higher than the default value of one second. If you do change the time interval between VRRP
advertisements on one router, change it on all participating routers.
If are using VRRP version 2, you must configure the timer values in multiple of whole seconds. For example a timer value of 3
seconds or 300 centisecs are valid and equivalent. However, a time value of 50 centisecs is invalid because it not a multiple of 1
second. If you are using VRRP version 3, you must configure the timer values in multiples of 25 centisecs.
If you are configured for VRRP version 2, the timer values must be in multiples of whole seconds. For example, timer value of
3 seconds or 300 centisecs are valid and equivalent. However, a timer value of 50 centisecs is invalid because it not is not
multiple of 1 second.
If are using VRRP version 3, you must configure the timer values in multiples of 25 centisecs.
To change the advertisement interval in seconds or centisecs, use the following command. A centisecs is 1/100 of a second.
1. Change the advertisement interval setting. INTERFACE-VRID mode advertise-interval seconds The range is from 1
to 255 seconds. The default is 1 second.
2. For VRRPv3, change the advertisement centisecs interval setting. INTERFACE-VRID mode advertise-interval
centisecs centisecs
The range is from 25 to 4075 centisecs in units of 25 centisecs.
The default is 100 centisecs.
The following example shows how to change the advertise interval using the advertise-interval command.
Dell(conf-if-te-1/1)#vrrp-group 111
Dell(conf-if-te-1/1-vrid-111)#advertise-interval 10
Dell(conf-if-te-1/1-vrid-111)#
The following example shows how to verify the advertise interval change using the show conf command
Dell(conf-if-te-1/1-vrid-111)#show conf
!
vrrp-group 111
advertise-interval 10
authentication-type simple 7 387a7f2df5969da4
no preempt
priority 255
virtual-address 10.10.10.1
virtual-address 10.10.10.2
virtual-address 10.10.10.3
virtual-address 10.10.10.10
Dell(conf-if-te-1/1-vrid-111)#
Track an Interface or Object
You can set the Dell Networking OS to monitor the state of any interface according to the virtual group.
Each VRRP group can track up to 12 interfaces and up to 20 additional objects, which may affect the priority of the VRRP
group. If the tracked interface goes down, the VRRP group’s priority decreases by a default value of 10 (also known as cost). If
the tracked interface’s state goes up, the VRRP group’s priority increases by 10.
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.
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Virtual Router Redundancy Protocol (VRRP)