Enabling dropping unknown multicast data

About dropping unknown multicast data

Unknown multicast data refers to multicast data for which no forwarding entries exist in the IGMP snooping forwarding table. This feature enables the device to forward unknown multicast data only to the router port. If the device does not have a router port, unknown multicast data will be dropped.

If you do not enable this feature, the unknown multicast data is flooded in the VLAN or VSI to which the data belongs.

Restrictions and guidelines

When dropping unknown IPv4 multicast data is enabled, the device also drops unknown IPv6 multicast data.

When dropping unknown multicast data is enabled, the device still forwards unknown multicast data out of router ports except the receiving router port.

Enabling dropping unknown multicast data for a VLAN

  1. Enter system view.

    system-view

  2. Enter VLAN view.

    vlan vlan-id

  3. Enable dropping unknown multicast data for the VLAN.

    igmp-snooping drop-unknown

    By default, dropping unknown multicast data is disabled for a VLAN. Unknown multicast data is flooded in the VLAN.

Enabling dropping unknown multicast data for a VSI

  1. Enter system view.

    system-view

  2. Enter VSI view.

    vsi vsi-name

  3. Enable dropping unknown multicast data for the VSI.

    igmp-snooping drop-unknown

    By default, dropping unknown multicast data is disabled for a VSI. Unknown multicast data is flooded in the VSI.