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2.6.7 IGMP Control
IGMP Snooping is the process of listening to IGMP traffic and is a feature that allows the
switch to
“
listen in
”
on the IGMP conversation between hosts and routers by processing the
layer 3 packets IGMP packets sent in a multicast network.
When IGMP snooping is enabled, this Residential Gateway analyses all the IGMP packets
between hosts connected to it and multicast routers in the network. When it hears an IGMP
report from a host for a given multicast group, it adds the host's port number to the multicast
list for that group. And, when it hears an IGMP Leave, it removes the host's port from the
table entry.
IGMP snooping can effectively reduce multicast traffic from streaming and other bandwidth
intensive IP applications. This gateway using IGMP snooping will only forward multicast
traffic to the hosts interested in that traffic. This reduction of multicast traffic reduces the
packet processing at the gateway and also reduces the workload at the end hosts.
Select
IGMP Control
from the
Switch Configuration
menu,
then
IGMP Control
screen
page shows up.
NAT
IGMP Proxy:
Enable or disable IGMP Proxy. When enabled, all clients attached to the
Residential Gateway will receive multicast data. Please note that IGMP Proxy and IGMP
Snooping can not be selected at the same time.
Proxy Fast Leave:
Enable or disable Proxy Fast Leave. When enabled, the Residential
Gateway removes the interface from the forwarding table immediately when the leave
message is received. Please ensure that only one host is attached to the each interface
when Fast Leave is enabled; otherwise, multicast traffic to other hosts attached to the
interface will be dropped.
Bridge
IGMP Snooping:
Enable or disable IGMP Snooping. When enabled, all clients that respond
with a join message will receive multicast data. Please note that IGMP Proxy and IGMP
Snooping can not be selected at the same time.
Snooping Fast Leave:
Enable or disable Snooping Fast Leave. When enabled, the
Residential Gateway removes the interface from the forwarding table immediately when the