To configure the Multicast Listener Discovery (MLD) last member query counter, use the ipv6 mld last-member-query-count command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ipv6 mld last-member-query-count count

no ipv6 mld 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 MLD Robustness variable.

Command Mode

Interface Configuration mode

User Guidelines

Use the ipv6 mld robustness command to change the MLD last member query counter.

Example

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

switchxxxxxx(config)# interface vlan 1
ipv6 mld last-member-query-count 3
exit

To configure the Multicast Listener Discovery (MLD) last member query interval, use the ipv6 mld last-member-query-interval command in Interface Configuration mode. To restore the default MLD query interval, use the no form of this command.

Syntax

ipv6 mld last-member-query-interval milliseconds

no ipv6 mld last-member-query-interval

Parameters

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

Default Configuration

The default MLD last member query interval is 1000 milliseconds.

Command Mode

Interface Configuration mode

User Guidelines

Use the ipv6 mld last-member-query-interval command to configure the MLD last member query interval on an interface.

Example

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

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ipv6 mld last-member-query-interval 1500
switchxxxxxx(config-if)# exit

To configure the frequency at which the switch sends Multicast Listener Discovery (MLD) host-query messages, use the ipv6 mld query-interval command in Interface Configuration mode. To return to the default frequency, use the no form of this command.

Syntax

ipv6 mld query-interval seconds

no ipv6 mld query-interval

Parameters

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

Default Configuration

The default MLD query interval is 125 seconds.

Command Mode

Interface Configuration mode

User Guidelines

Use the ipv6 mld query-interval command to configure the frequency at which the MLD querier sends MLD host-query messages from an interface. The MLD 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 MLD querier sends MLD host-query messages to 180 seconds:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ipv6 mld query-interval 180
switchxxxxxx(config-if)# exit

To configure the maximum response time advertised in Multicast Listener Discovery (MLD) queries, use the ipv6 mld query-max-response-time command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ipv6 mld query-max-response-time seconds

no ipv6 mld query-max-response-time

Parameters

• seconds—Maximum response time, in seconds, advertised in MLD 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 MLD query message before the router deletes the group.

This command controls how much time the hosts have to answer an MLD 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)# ipv6 mld query-max-response-time 8
switchxxxxxx(config-if)# exit

To configure the Multicast Listener Discovery (MLD) robustness variable, use the ipv6 mld robustness command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ipv6 mld robustness count

no ipv6 mld 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 ipv6 mld robustness command to change the MLD robustness variable.

Example

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

switchxxxxxx(config)# interface vlan 1
switchxxxxxx(config-if)# ipv6 mld robustness 3
switchxxxxxx(config-if)# exit

To configure which version of Multicast Listener Discovery Protocol (MLD) the router uses, use the ipv6 mld version command in Interface Configuration mode. To restore the default value, use the no form of this command.

Syntax

ipv6 mld version {1 | 2}

no ipv6 mld version

Parameters

• 1—MLD Version 1.

• 2—MLD Version 2.

Default Configuration

1

Command Mode

Interface Configuration mode

User Guidelines

Use the command to change the default version of MLD.

Example

The following example configures the router to use MLD Version 1:

switchxxxxxx(config)# interface vlan 100
switchxxxxxx(config-if)# ipv6 mld version 1
switchxxxxxx(config-if)# exit

To display multicast-related information about an interface, use the show ipv6 mld interface command in User EXEC mode.

Syntax

show ipv6 mld interface [interface-id]

Parameters

• interface-id—Interface identifier.

Command Mode

User EXEC mode

User Guidelines

If you omit the optional interface-id argument, the show ipv6 mld interface command displays information about all interfaces.

Example

The following is sample output from the show ipv6 mld interface command for Ethernet interface 2/1/1:

switchxxxxxx# show ipv6 mld interface vlan 100
VLAN 100 is up
 Administrative MLD Querier IPv6 address is FE80::260:3EFF:FE86:5649
 Operational MLD Querier IPv6 address is FE80::260:3EFF:FE86:5649
 Current MLD version is 3
 Administrative MLD robustness variable is 2 seconds
 Operational MLD robustness variable is 2 seconds
 Administrative MLD query interval is 125 seconds
 Operational MLD query interval is 125 seconds
 Administrative MLD max query response time is 10 seconds
 Operational MLD 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