Configuring Fast Leave Mode

Configure fast (immediate) leave mode to alter the leave processing on fast leave enabled IGMPv2, IGMPv3, and IGMP snoop interfaces. Normal IGMP behavior is skipped. Fast leave mode provides one command that controls all IGMP fast leave enabled interfaces.

Before you begin

  • You must enable explicit-host-tracking before configuring fast-leave mode for IGMPv3. For more information on enabling explicit-host-tracking, see Configuring explicit host tracking.

About this task

If a single user connects to an interface, you do not need to track if other users exist on the interface to perform the fast leave. In cases like this, you must change the mode to one-user.

Important

Important

Fast leave mode applies only to fast leave enabled IGMP interfaces.

You can configure IGMP on a VRF instance the same way you configure the Global Router except that you must use VRF Router Configuration mode.

Procedure

  1. Enter Global Configuration mode:

    enable

    configure terminal

  2. View the current fast leave mode:

    show ip igmp sys

    Note

    Note

    This command is not supported on a node configured as the DvR Leaf within a DvR domain.

  3. Configure fast leave mode:

    ip igmp immediate-leave-mode <multiple-user|one-user>

Example

Change the mode to one-user.

Switch:1(config)#ip igmp immediate-leave-mode one-user

Variable definitions

Use the data in the following table to use the ip igmp immediate-leave-mode command.

Variable

Value

multiple-user|one-user

multiple-user removes from the group only the IGMP member who sent the leave message. Traffic does not stop if other receivers exist on the interface port. This configuration is the default.

one-user removes all group members on a fast leave enabled interface port after receiving the first leave message from a member. This behavior is the same as the conventional fast leave process.