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声明：转自 Cisco.com

ip igmp join-group

To have the router join a multicast group, use the ip igmp join-group command in interface configuration mode. To cancel membership in a multicast group, use the no form of this command.

ip igmp join-group group-address [source source-address]

no ip igmp join-group group-address [source source-address]

Usage Guidelines

IP packets that are addressed to the group address are passed to the IP client process in the Cisco IOS software.

If all the multicast-capable routers and access servers that you administer are members of a multicast group, pinging that group causes all routers to respond, which can be a useful administrative and debugging tool.

Another reason to have a router join a multicast group is when other hosts on the network have an Interior Gateway Routing Protocol (IGRP) configuration that prevents them from correctly answering Internet Group Management Protocol (IGMP) queries. Having the router join the multicast group causes upstream routers to maintain multicast routing table information for that group and keep the paths for that group active.

Examples

In the following example, the router joins multicast group 225.2.2.2:

ip igmp join-group 225.2.2.2 

In the following example, the router joins multicast group 225.2.2.2 and includes the IP source address 1.1.1.1:

ip igmp join-group 225.2.2.2 source 1.1.1.1 

Related Commands