hello-interval (VRRP)

Configures the interval at which master Virtual Router Redundancy Protocol (VRRP) routers advertise their existence to the backup VRRP routers.
Syntax
hello-interval [ msec ] interval
no hello-interval [ msec ] interval
Command Default

Hello messages from VRRP master routers are sent to backup routers every second.

Parameters
msec interval
Interval, in milliseconds, at which a master VRRP router advertises its existence to the backup VRRP routers. Valid values range from 100 through 84000. The default is 1000. VRRP-E does not support the hello message interval in milliseconds.
interval
Sets the interval, in seconds, for which a VRRP backup router waits for a hello message from the VRRP master router before determining that the master is offline. Valid values range from 1 through 84. The default value is 1.
Modes

VRID interface configuration mode

Usage Guidelines

A VRRP master router periodically sends hello messages to the backup routers. The backup routers use the hello messages as verification that the master is still online. 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 that point, the backup router with the highest priority becomes the new master router.

By default, the dead interval is internally derived from the hello interval. It is equal to 3 times the hello interval plus the skew time, where the skew time is equal to (256 minus the priority) divided by 256. Generally, if you change the hello interval on the master VRRP router using the hello-interval command, you also should also change the dead interval on the VRRP backup routers using the dead-interval command.

The hello-interval command is configured only on master VRRP routers and is supported by VRRP and VRRP-E.

The no form resets the hello message interval to its default value of 1000 milliseconds (1 second).

Note: VRRP-E does not support the hello message interval in milliseconds.
Examples

The following example enables advertisements from the VRRP master router and sets the hello message interval to 10,000 milliseconds. 

device# configure terminal
device(config)# router vrrp
device(config)# interface ethernet 1/1/6
device(config-if-e1000-1/1/6)# ip address 10.53.5.1/24
device(config-if-e1000-1/1/6)# ip vrrp vrid 1
device(config-if-e1000-1/1/6-vrid-1)# owner
device(config-if-e1000-1/1/6-vrid-1)# ip address 10.53.5.1
device(config-if-e1000-1/1/6-vrid-1)# hello-interval msec 10000
device(config-if-e1000-1/1/6-vrid-1)# activate
VRRP router 1 for this interface is activating

The following example enables advertisements from the VRRP-E master router and sets the hello message interval to 15 seconds. 

device# configure terminal
device(config)# router vrrp-extended
device(config)# interface ethernet 1/1/5
device(config-if-e1000-1/1/5)# ip address 10.53.5.3/24
device(config-if-e1000-1/1/5)# ip vrrp-extended vrid 2
device(config-if-e1000-1/1/5-vrid-2)# backup priority 50 track-priority 10 
device(config-if-e1000-1/1/5-vrid-2)# ip-address 10.53.5.1
device(config-if-e1000-1/1/5-vrid-2)# hello-interval 15
device(config-if-e1000-1/1/5-vrid-2)# activate
VRRP router 2 for this interface is activating
Parent topic: Commands D through H