2.3 Single Area OSPF Configuration  
  2.3.5 Configuring OSPF timers  
OSPF routers must have the same hello intervals and the same dead intervals to exchange information. By default, the dead interval is four times the value of the hello interval. This means that a router has four chances to send a hello packet before being declared dead.

On broadcast OSPF networks, the default hello interval is 10 seconds and the default dead interval is 40 seconds. On nonbroadcast networks, the default hello interval is 30 seconds and the default dead interval is 120 seconds. These default values result in efficient OSPF operation and seldom need to be modified.

A network administrator is allowed to choose these timer values. A justification that OSPF network performance will be improved is needed prior to changing the timers. These timers must be configured to match those of any neighboring router.

To configure the hello and dead intervals on an interface, use the following commands:

Router(config-if)#ip ospf hello-interval seconds
Router(config-if)#ip ospf dead-interval seconds

 

Lab Activity

Lab Exercise: Configuring OSPF Timers

This lab is to setup OSPF timers.

   
 

Lab Activity

e-Lab Activity: Configuring OSPF Timers

In this lab, the student will adjust OSPF timers to maximize efficiency of the network.

   
 

Web Links

timers OSPF

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