Disabling a port from becoming a dynamic router port

A receiver host might send IGMP general queries or PIM hello messages for testing purposes. On the Layer 2 device, the port that receives either of the messages becomes a dynamic router port. Before the aging timer for the port expires, the following problems might occur:

• All multicast data for the VLAN to which the port belongs flows to the port. Then, the port forwards the data to attached receiver hosts. The receiver hosts will receive multicast data that it does not want to receive.

• The port forwards the IGMP general queries or PIM hello messages to its upstream Layer 3 devices. These messages might affect the multicast routing protocol state (such as the IGMP querier or DR election) on the Layer 3 devices. This might further cause network interruption.

To solve these problems, you can disable a port from becoming a dynamic router port. This also improves network security and the control over receiver hosts.

This configuration and the static router port configuration do not interfere with each other.

1. Enter system view.

   system-view

2. Enter Layer 2 interface view.

   • Enter Layer 2 Ethernet interface view.

     interface interface-type interface-number

   • Enter Layer 2 aggregate interface view.

     interface bridge-aggregation interface-number

3. Disable the port from becoming a dynamic router port.

   igmp-snooping router-port-deny [ vlan vlan-list ]

   By default, a port is allowed to become a dynamic router port.