Configuring Fast Leave Processing; Disabling A Port Or A Group Of Ports From Changing Into Dynamic Router Ports - HP A6600 Configuration Manual

Configuring fast leave processing

The fast leave processing feature allows the router to process IGMP leave messages in a fast way. With
the fast leave processing feature enabled, when receiving an IGMP leave message on a port, the router
immediately removes that port from the outgoing port list of the forwarding table entry for the indicated
group. Then, when receiving IGMP group-specific queries for that multicast group, the router will not
forward them to that port.
In VLANs where only one host is attached to each port, fast leave processing helps improve bandwidth
and resource usage. However, if fast leave processing is enabled on a port to which more than one host
is attached, when one host leaves a multicast group, the other hosts attached to the port and interested in
the same multicast group will fail to receive multicast data for that group. Therefore, if the function of
dropping unknown multicast traffic is already enabled on the router or in the VLANs, the fast leave
processing function should not be enabled.
Configuring fast leave processing globally
To do...
1. Enter system view.
2. Enter IGMP-snooping view.
3. Enable fast leave processing.
Configuring fast leave processing on a port or a group of ports
To do...
1. Enter system view.
2. Enter Ethernet interface/Layer
2 aggregate interface view or
port group view.
3. Enable fast leave processing.
Disabling a port or a group of ports from changing into
dynamic router ports
At present, the following problems exist in a multicast access network:
After receiving an IGMP general query or a PIM Hello message from a connected host, a router port
•
becomes a dynamic router port. Before its timer expires, this dynamic router port will receive all
multicast packets within the VLAN it belongs to and forward them to the host, thus affecting normal
multicast reception of the host.
• In addition, the IGMP general query or PIM Hello message sent from the host affects the multicast
routing protocol state on Layer 3 devices, such as the IGMP querier or DR election, and might further
cause network interruption.
Use the command...
system-view
igmp-snooping
fast-leave [ vlan vlan-list ]
Use the command...
system-view
interface interface-type interface-number
port-group manual port-group-name
igmp-snooping fast-leave [ vlan vlan-list ]
22
Remarks
—
—
Required.
Disabled by default.
Remarks
—
Required.
Use either approach.
Required.
Disabled by default.