Technical Documentation

Configuring IGMP Snooping (J-Web Procedure)

IGMP snooping regulates multicast traffic in a switched network. With IGMP snooping enabled, the EX Series switch monitors the IGMP transmissions between a host (a network device) and a multicast router, keeping track of the multicast groups and associated member interfaces. The switch uses that information to make intelligent multicast-forwarding decisions and forward traffic to the intended destination interfaces.

You can configure IGMP snooping on one or more VLANs to allow the switch to examine IGMP packets and make forwarding decisions based on packet content. By default, IGMP snooping is enabled on EX Series switches.

To enable IGMP snooping and configure individual options using the J-Web interface:

  1. Select Configure > Switching > IGMP Snooping.

    Note: After you make changes to the configuration in this page, you must commit the changes for them to take effect. To commit all changes to the active configuration, select Commit Options > Commit. See Using the Commit Options to Commit Configuration Changes for details about all commit options.

  2. Click one:
    • Add—Creates an IGMP snooping configuration for the VLAN.
    • Edit—Modifies an IGMP snooping configuration for the VLAN.
    • Delete—Deletes a selected VLAN from the IGMP snooping configuration.

    When you are adding or editing an IGMP snooping configuration, enter information as described in Table 1

  3. Click OK to apply changes to the configuration or click Cancel to cancel without saving changes.

To disable IGMP snooping on a VLAN, select the VLAN from the list and click Disable.

Table 1: IGMP Snooping Configuration Fields



Your Action


Specifies the VLAN on which to enable IGMP snooping.

Select a VLAN from the list to add it to the snooping configuration.

Immediate Leave

Immediately removes a multicast group membership from an interface when it receives a leave message from that interface without waiting for any other IGMP messages to be exchanged (IGMPv2 only).

To enable the option, select the check box.

To disable the option, clear the check box.

Robust Count

Specifies the number of timeout intervals the switch waits before timing out a multicast group.

Type a value.

Interfaces List

Statically configures an interface as a switching interface toward a multicast router (the interface to receive multicast traffic).

Click one:

  • Add—Adds an interface to the IGMP snooping configuration.
    1. Select an interface from the list.
    2. Select Multicast Router Interface.
    3. Type the maximum number of groups an interface can join.
    4. In Static, choose one:
      • Click Add, type a group IP address, and click OK.
      • Select a group and click Remove to remove the group membership.
  • Edit—Edits the interface settings for the IGMP snooping configuration.
  • Remove—Deletes an interface configured for IGMP snooping.

Published: 2010-05-03