20
Step Command
Remarks
interface view or Layer 2
aggregate interface view.
interface-number
3.
Configure the port as a
simulated member host.
igmp-snooping host-join
group-address
[
source-ip
source-address
]
vlan
vlan-id
By default, the port is not a
simulated member host.
Enabling fast-leave processing
This feature enables the switch to immediately remove a port from the forwarding entry for a
multicast group when the port receives a leave massage.
Configuration restrictions and guidelines
When you enable fast-leave processing, follow these restrictions and guidelines:
•
Do not enable fast-leave processing on a port that has multiple receiver hosts in a VLAN. If
fast-leave processing is enabled, the remaining receivers cannot receive multicast data for a
group after a receiver leaves that group.
•
You can enable fast-leave processing globally for all ports in IGMP-snooping view or for a port
in interface view. For a port, the port-specific configuration takes priority over the global
configuration.
Enabling fast-leave processing globally
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IGMP-snooping view.
igmp-snooping
N/A
3.
Enable fast-leave processing
globally.
fast-leave
[
vlan vlan-list
]
By default, fast-leave processing
is disabled globally.
Enabling fast-leave processing on a port
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view.
interface interface-type
interface-number
N/A
3.
Enable fast-leave processing
on the port.
igmp-snooping
fast-leave
[
vlan
vlan-list
]
By default, fast-leave processing
is disabled on a port.
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 multicast
routers. These messages might affect the multicast routing protocol state (such as the IGMP
querier or DR election) on the multicast routers. This might further cause network interruption.
