Cisco Cisco IOS Software Release 12.2(15)T

To set the interval during which at least one hello packet must be received from a neighbor before the 
router declares that neighbor down, use the ip ospf dead-interval command in interface configuration 
mode. To restore the default value, use the no form of this command.

ip ospf dead-interval {seconds | minimal hello-multiplier multiplier}

seconds: Four times the interval set by the ip ospf hello-interval command.

Interface configuration

The dead interval is advertised in OSPF hello packets. This value must be the same for all networking 
devices on a specific network.

Specifying a smaller dead interval (seconds) will give faster detection of a neighbor being down and 
improve convergence, but might cause more routing instability.

By specifying the minimal and hello-multiplier keywords with a multiplier argument, you are enabling 
OSPF fast hello packets. The minimal keyword sets the dead interval to 1 second, and the 
hello-multiplier value sets the number of hello packets sent during that 1 second, thus providing 
subsecond or “fast” hello packets. 

Interval (in seconds) during which the router must receive at least one hello 
packet from a neighbor or else that neighbor is removed from the peer list 
and does not participate in routing. The range is 1 to 65535. The value must 
be the same for all nodes on the network.

Sets the dead interval to 1 second. Using this keyword requires that the 
hello-multiplier keyword and multiplier argument are also configured.

hello-multiplier 
multiplier

Integer value in the range from 3 to 20, representing the number of hello 
packets sent during 1 second.

10.0

This command was introduced.

12.0(23)S

The minimal keyword, hello-multiplier keyword and multiplier argument 
were added to allow Open Shortest Path First (OSPF) support for fast hello 
packets.

12.2(27)SBC

This command was integrated into Cisco IOS Release 12.2(27)SBC.