Install guide

IP Multicasting 19
Static IGMP
Static IGMP forwards multicast data over specific interfaces and ports. It is an
alternative to dynamic IGMP, and is useful for network segments that have no
multicast group members or have hosts that are unable to report group
membership with IGMP. A dynamic IGMP configuration does not send
multicast traffic to these network segments.
Figure 2 shows a switch forwarding the multicast stream to a set-top box after a
user specifies that group 224.1.1.1 multicast data should be forwarded out of
port 4 of VLAN1. Unlike conventional IGMP membership, this user-specified
static membership never times out. You can also filter some IGMP debug
messages by source IP address and group destination address.
Figure 2: Forwarding multicast data over a specific interface and port
To enable IGMP on the switch, use the command:
enable ip igmp
To enable IGMP on a specific interface, use the command:
enable ip igmp interface=interface
To create the static IGMP association, use the command:
create ip igmp destination=ipaddress interface=interface
[port={all|port-list}]
The multicast data for the group specified by the destination parameter is
forwarded over the ports specified by the port parameter. If the port parameter
is not entered, the association defaults to all ports belonging to the interface.
To display information about the static IGMP association, use the command:
show ip igmp [interface=interface] [destination=ipaddress]
1
2
34
VLAN1
Rapier i
Multicast stream transmitter
Group 224.1.1.1
Set-top box,
ADSL Switch, etc
IGMP1