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Specifying Multicast Groups
You can use a standard-format or extended-format
IP access list to specify the multicast groups that a host can join.
ip
igmp access-group
- Use to restrict hosts on this subnetwork to join only
multicast groups that appear on the specified IP access list.
- When this feature is configured, the access list is queried
whenever the router receives an IGMPv2 report requesting membership
of a group, and IGMPv3 ChangeToInclude or IsExclude reports. The request
is rejected if the access list query fails.
- The ip igmp access-group command
accepts standard or extended-format access lists. Because the extended
format enables you to specify both the source address and the destination
group address, the source address must be set to any. For example, access-list test permit ip host 224.128.64.32 any.
- Note that in the access list specified when you issue
this command, the group is specified before the source.
- Example
- host1:boston(config-if)#ip igmp access-group
boston-list
- Use the no version to dissociate
the interface from an access list and to enable hosts on the interface
to join any multicast group.
- See ip igmp access-group.
ip
igmp access-source-group
- Use to restrict hosts on this subnetwork to membership
in those (S,G) pairs (also known as channels)
included on the specified IP access list.
- When this feature is configured, both source and group
addresses query the associated access list whenever the router receives
an IGMPv3 report requesting membership of the (S,G) pairs (that is,
the router receives an IGMPv3 ChangeToInclude, IsInclude, or AllowNewSource
group report). The request is rejected if the access list query fails.
- The ip igmp access-source-group command accepts standard or extended-format access lists. The extended
format enables you to specify both the source address and the destination
group address; for example, access-list test permit ip host 10.1.1.1 host 224.128.64.32. Typically, you use the extended-format access list. If you instead
use the standard-format access list, you explicitly specify the source
address to create the access list, but the group address is implicitly
assumed to be any,
- Note that in the access list specified when you issue
this command, the source is specified before the group.
- Example
- host1:boston(config-if)#ip igmp access-source-group
dallas-list
- Use the no version to remove
any access list restriction.
- See ip igmp access-source-group.
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