Cisco Systems 3750E Configuring Optional Igmp Features, Ip pim query-interval seconds, 42-28

Chapter 42 Configuring IP Multicast Routing

Configuring Optional IGMP Features

	Command	Purpose
Step 4
	end	Return to privileged EXEC mode.
Step 5
	show running-config	Verify your entries.
Step 6
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return to the default setting, use the no ip pim spt-threshold{kbps infinity} global configuration command.

Modifying the PIM Router-Query Message Interval

PIM routers and multilayer switches send PIM router-query messages to find which device will be the DR for each LAN segment (subnet). The DR is responsible for sending IGMP host-query messages to all hosts on the directly connected LAN.

With PIM DM operation, the DR has meaning only if IGMPv1 is in use. IGMPv1 does not have an IGMP querier election process, so the elected DR functions as the IGMP querier. With PIM-SM operation, the DR is the device that is directly connected to the multicast source. It sends PIM register messages to notify the RP that multicast traffic from a source needs to be forwarded down the shared tree. In this case, the DR is the device with the highest IP address.

Beginning in privileged EXEC mode, follow these steps to modify the router-query message interval. This procedure is optional.

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface interface-id	Specify the interface to be configured, and enter interface configuration
		mode.
Step 3
	ip pim query-interval seconds	Configure the frequency at which the switch sends PIM router-query
		messages.
		The default is 30 seconds. The range is 1 to 65535.
Step 4
	end	Return to privileged EXEC mode.
Step 5
	show ip igmp interface [interface-id]	Verify your entries.
Step 6
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To return to the default setting, use the no ip pim query-interval[seconds] interface configuration command.

Configuring Optional IGMP Features

These sections contain this configuration information:

•Default IGMP Configuration, page 42-29

•Configuring the Switch as a Member of a Group, page 42-29(optional)

•Controlling Access to IP Multicast Groups, page 42-30(optional)

•Changing the IGMP Version, page 42-31(optional)

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
42-28	OL-9775-02