To configure the Internet Group Management Protocol (IGMP) last member query counter, use the ip igmp last-member-query-count command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ip igmp last-member-query-count count

no ip igmp last-member-query-count

Parameters

count—The number of times that group- or group-source-specific queries are sent upon receipt of a message indicating a leave. (Range: 1–7)

Default Configuration

A value of IGMP Robustness variable.

Command Mode

Interface Configuration mode

User Guidelines

Use the ip igmp robustness command to change the IGMP last member query counter.

Example

The following example changes a value of the IGMP last member query counter to 3:

switchxxxxxx(config)# interface vlan 1
switchxxxxxx(config-if)# ip igmp last-member-query-count 3
switchxxxxxx(config-if)# exit

To configure the Internet Group Management Protocol (IGMP) last member query interval, use the ip igmp last-member-query-interval command in Interface Configuration mode. To restore the default IGMP query interval, use the no form of this command.

Syntax

ip igmp last-member-query-interval milliseconds

no ip igmp last-member-query-interval

Parameters

• milliseconds—Interval, in milliseconds, at which IGMP group-specific host query messages are sent on the interface. (Range: 100–25500).

Default Configuration

The default IGMP last member query interval is 1000 milliseconds.

Command Mode

Interface Configuration mode

User Guidelines

Use the ip igmp last-member-query-interval command to configure the IGMP last member query interval on an interface.

Example

The following example shows how to increase the the IGMP last member query interval to 1500 milliseconds:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ip igmp last-member-query-interval 1500
switchxxxxxx(config-if)# exit

To configure the frequency at which the IGMP querier sends Internet Group Management Protocol (IGMP) host-query messages from an interface, use the ip igmp query-interval command in Interface Configuration mode. To restore the default IGMP query interval, use the no form of this command.

Syntax

ip igmp query-interval seconds

no ip igmp query-interval

Parameters

• seconds—Frequency, in seconds, at which the switch sends IGMP query messages from the interface. The range is from 30 to 18000.

Default Configuration

The default IGMP query interval is 125 seconds.

Command Mode

Interface Configuration mode

User Guidelines

Use the ip igmp query-interval command to configure the frequency at which the IGMP querier sends IGMP host-query messages from an interface. The IGMP querier sends query-host messages to discover which multicast groups have members on the attached networks of the router.

The query interval must be bigger than the maximum query response time.

Example

The following example shows how to increase the frequency at which the IGMP querier sends IGMP host-query messages to 180 seconds:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ip igmp query-interval 180
switchxxxxxx(config-if)# exit

To configure the maximum response time advertised in Internet Group Management Protocol (IGMP) queries, use the ip igmp query-max-response-time command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ip igmp query-max-response-time seconds

no ip igmp query-max-response-time

Parameters

• seconds—Maximum response time, in seconds, advertised in IGMP queries. (Range: 5–20)

Default Configuration

10 seconds.

Command Mode

Interface Configuration mode

User Guidelines

This command controls the period during which the responder can respond to an IGMP query message before the router deletes the group.

This command controls how much time the hosts have to answer an IGMP query message before the router deletes their group. Configuring a value of fewer than 10 seconds enables the router to prune groups faster.

The maximum query response time must be less than the query interval.

Note. If the hosts do not respond fast enough, they might be pruned inadvertently. Therefore, the hosts must know to respond faster than 10 seconds (or the value you configure).

Example

The following example configures a maximum response time of 8 seconds:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ip igmp query-max-response-time 8
switchxxxxxx(config-if)# exit

To configure the Internet Group Management Protocol (IGMP) robustness variable, use the ip igmp robustness command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ip igmp robustness count

no ip igmp robustness

Parameters

• count—The number of expected packet loss on a link. Parameter range. (Range: 1–7).

Default Configuration

The default value is 2.

Command Mode

Interface Configuration mode

User Guidelines

Use the ip igmp robustness command to change the IGMP robustness variable.

Example

The following example changes a value of the IGMP robustness variable to 3:

switchxxxxxx(config)# interface vlan 1
switchxxxxxx(config-if)# ip igmp robustness 3
switchxxxxxx(config-if)# exit

To configure which version of Internet Group Management Protocol (IGMP) the router uses, use the ip igmp version command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ip igmp version {1 | 2 | 3}

no ip igmp version

Parameters

• 1—IGMP Version 1.

• 2—IGMP Version 2.

• 3—IGMP Version 3.

Default Configuration

3

Command Mode

Interface Configuration mode

User Guidelines

Use the commnad to change the default version of IGMP>

Example

The following example configures the router to use IGMP Version 2:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ip igmp version 2
switchxxxxxx(config-if)# exit

To display multicast-related information about an interface, use the show ip igmp interface command in User EXEC mode.

Syntax

show ip igmp interface [interface-id]

Parameters

• interface-id—(Optional) Interface identifier.

Command Mode

User EXEC mode

User Guidelines

If you omit the optional interface-id argument, the show ip igmp interface command displays information about all interfaces.

Example

The following is sample output from the show ip igmp interface command for Ethernet interface 2/1/1:

switchxxxxxx# show ip igmp interface vlan 100
VLAN 100 is up
 Administrative IGMP Querier IP address is 1.1.1.1
 Operational IGMP Querier IP address is 1.1.1.1
 Current IGMP version is 3
 Administrative IGMP robustness variable is 2 seconds
 Operational IGMP robustness variable is 2 seconds
 Administrative IGMP query interval is 125 seconds
 Operational IGMP query interval is 125 seconds
 Administrative IGMP max query response time is 10 seconds
 Operational IGMP max query response time is 10 seconds
 Administrative Last member query response interval is 1000 milliseconds
 Operational Last member query response interval is 1000 milliseconds