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multicast list for that group. And, when the Gateway hears an IGMP Leave, it removes the host's
port from the table entry.
IGMP snooping can very effectively reduce multicast traffic from streaming and other bandwidth
intensive IP applications. A 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 (at the cost of needing additional memory to handle the multicast tables) and also
reduces the workload at the end hosts since their network cards (or operating system) will not
have to receive and filter all the multicast traffic generated in the network.
Command
Parameter Description
Gateway(config)# ip igmp
snooping
When enabled, the Gateway will monitor
network traffic and determine which hosts
to receive multicast traffic.
Gateway(config)# ip igmp
snooping immediate-leave
Enable immediate leave function.
No command
Gateway(config)# no ip igmp
snooping
Disable IGMP/MLD Snooping function.
Gateway(config)# no ip igmp
snooping immediate-leave
Disable immediate leave function.
Show command
Gateway(config)#show ip igmp
snooping
Show current IGMP/MLD snooping status
including immediate leave function.
Gateway(config)#show ip igmp
snooping groups
Show IGMP/MLD group table.
Gateway(config)#show ip igmp
snooping status
Show IGMP/MLD Snooping status.
6. Configure Routing
Command
Parameter Description
Gateway(config)# ip route static
Enable static route function. A static route
is a pre-determined pathway that packets
can travel to reach a specific destination
network.
Gateway(config)# ip route static
[1-20]
[1-20]
Specify the index number of static route.
Gateway(config-static-route-
no.)# active
Enable the static route specified.
Gateway(config-static-route-
no.)# address [A.B.C.D]
[255.x.x.x] [A.B.C.D]
[A.B.C.D]
Specify the destination IP address of the
static route
[255.x.x.x]
Specify the subnet mask of the destination
network of the static route.
[A.B.C.D]
Specify the IP address of a gateway
through which this static route will send the
packets to the destination network.
Gateway(config-static-route-
no.)# address [wan | lan]
[wan | lan]
Specify an interface of the Residential
Gateway from which the static route will
forward the packets to the destination
network.