25
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.
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.
To disable a port from becoming a dynamic router 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.
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.
This configuration does not affect
the static router port configuration.
Enabling inner VLAN ID-based forwarding
Use this feature to enable a port to create and maintain IGMP snooping entries based on the inner
VLAN IDs of the received double-tagged IGMP packets.
To enable inner VLAN ID-based forwarding:
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 inner VLAN ID-based
forwarding.
igmp-snooping cvid-forward
By default, inner VLAN ID-based
forwarding is disabled on a port.
The port performs outer VLAN