3Com Switch 7750 Configuration Guide Guide

IGMP Configuration Tasks 415
c
CAUTION:
■ If the number of joined multicast groups on the interface exceeds the
user-defined limit, new groups are not allowed to join any more.
■ If the number of existing IGMP multicast groups has exceeded the configured
limit on the number of joined multicast groups on the interface, the system will
delete some existing multicast groups automatically until the number of
multicast groups on the interface is conforming to the conferred limit.
Configuring Router
Ports to Join the
Specified Multicast
Group
Generally, the host running IGMP will respond to the IGMP query packets of the
multicast switch. If the host cannot respond for some reason, the multicast switch
may think that there is no members of the multicast group in this network
segment and then cancel the corresponding paths.
In order to avoid such cases, you must configure a port of the VLAN interface of
the switch as a router port to add it to the multicast group. When the port receives
IGMP query packets, the multicast switch will respond to it. As a result, the
network segment that the Layer 3 interfaces lie in can continue to receive
multicast packets.
Limit the range of multicast
groups that the interface
serves
igmp group-policy
acl-number vlan vlan-id
Optional
By default, the filter is not
configured, that is, any
multicast group is permitted
on the port.
The port must belong to the
IGMP-enabled VLAN specified
in the command. Otherwise,
the command does not take
effect.
Table 331 Configure IGMP multicast groups on the interface
Operation Command Description
Table 332 Configure router ports to join the specified multicast group
Operation Command Description
Enter system view system-view -
Enable the multicast routing
protocol
multicast routing-enable Required
Enter VLAN interface view
interface Vlan-interface
interface-number
-
Enable IGMP on the current
interface
igmp enable
Required
IGMP is disabled on the
interface by default.
Configure router ports to join
a multicast group
igmp host-join
group-address port
interface-list
Optional
By default, the router port
does not join in any multicast
group.
Quit VLAN interface view. quit -
Enter Ethernet port view
interface interface-type
interface-number
-