3Com Switch 4800G 24-Port Configuration Manual page 562

562 C 42: IGMP S
HAPTER
n
Configuring Fast Leave
Processing
C
NOOPING ONFIGURATION
To avoid this situation from happening, you can enable simulated joining on a port
of the switch, namely configure the port as a simulated member host for a
multicast group. When an IGMP query is heard, the simulated host gives a
response. Thus, the switch can continue receiving multicast data.
A simulated host acts like a real host, as follows:
When a port is configured as a simulated member host, the switch sends an
■
unsolicited IGMP report through that port.
After a port is configured as a simulated member host, the switch responds to
■
IGMP general queries by sending IGMP reports through that port.
When the simulated joining function is disabled on a port, the switch sends an
■
IGMP leave group message through that port.
Follow these steps to configure simulated joining:
To do...
Enter system view
Enter the
corresponding view
Configure simulated (*, G) or (S, G) joining igmp-snooping
Each simulated host is equivalent to an independent host. For example, when
■
receiving an IGMP query, the simulated host corresponding to each
configuration responds respectively.
Unlike a static member port, a port configured as a simulated member host will
■
age out like a dynamic member port.
The fast leave processing feature allows the switch to process IGMP leave group
messages in a fast way. With the fast leave processing feature enabled, when
receiving an IGMP leave group message on a port, the switch 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 switch 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.
Configuring fast leave processing globally
Follow these steps to configure fast leave processing globally:
Use the command...
system-view
Enter Ethernet port interface
view interface-type
interface-number
Enter port group port-group { manual
view port-group-name |
aggregation agg-id }
host-join
group-address
[ source-ip
source-address ] vlan
vlan-id
Remarks
-
Use either command
Required
Disabled by default