4000 Router Series IP Multicast Configuration Guide

Enabling IGMP fast-leave processing

In some applications, such as ADSL dial-up networking, only one multicast receiver host is attached to an

interface of the IGMP querier. To allow fast response to the leave messages of the host when it switches

frequently from one multicast group to another, you can enable fast-leave processing on the IGMP

querier.

With IGMP fast-leave processing enabled, after receiving an IGMP leave message from a host, the IGMP

querier directly sends a leave notification to the upstream without sending IGMP group-specific queries

or IGMP group-and-source-specific queries. This reduces leave latency and preserves the network

bandwidth.

The IGMP fast-leave processing configuration takes effect only if the device is running IGMPv2 or

IGMPv3.

To enable IGMP fast-leave processing:

Ste

Command Remarks

1. Enter system view.

system-view N/A

2. Enter interface view.

interface interface-type

interface-number

N/A

3. Enable IGMP fast-leave

processing.

igmp fast-leave [ group-policy

acl-number ]

Disabled by default.

Displaying and maintaining IGMP

CAUTION:

The reset igmp group command might cause multicast data transmission failures.

Execute display commands in any view and reset commands in user view.

Task Command

Display IGMP group information.

display igmp [ vpn-instance vpn-instance-name ] group [ group-address |

interface interface-type interface-number ] [ static | verbose ]

Display IGMP information.

display igmp[ vpn-instance vpn-instance-name ] interface [ interface-type

interface-number ] [ verbose ]

Remove all the dynamic IGMP

group entries of an IGMP group or

all IGMP groups.

reset igmp [ vpn-instance vpn-instance-name ] group { all | interface

interface-type interface-number { all | group-address [ mask { mask |

mask-length } ] [ source-address [ mask { mask | mask-length } ] ] } }

NOTE:

The reset igmp group command cannot remove static IGMP group entries.