ip pim-sparse hello-interval

Syntax

ip pim-sparse hello-interval <INTERVAL-VALUE>

no ip pim-sparse hello-interval

Description

Configures the frequency at which the router transmits PIM hello messages on the current interface.

The no form of this command removes the currently configured value and sets to the default of 30 seconds.

Command context

config-if

config-if-vlan

config-lag-if

Parameters

<INTERVAL-VALUE>

Specifies the frequency at which PIM Hello messages are transmitted on this interface. Default: 30 seconds. Range: 5-300.

Authority

Administrators

Usage

  • The router uses hello packets to inform neighbor routers of its presence.

  • The router also uses this setting to compute the hello holdtime, which is included in hello packets sent to neighbor routers.

  • Hello holdtime tells neighbor routers how long to wait for the next hello packet from the router. If another packet does not arrive within that time, the router removes the neighbor adjacency on that interface from the PIM adjacency table, which removes any flows running on that interface.

  • Shortening the hello interval reduces the hello holdtime. If they do not receive a new hello packet when expected, it changes how quickly other routers stop sending traffic to the router.

Example

Configuring and removing sparse hello-interval:

switch(config)# interface 1/1/4
switch(config-if)# ip pim-sparse hello-interval 60
switch(config-if)# no ip pim-sparse hello-interval