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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 18 Configuring IGMP Snooping
Configuring IGMP Filtering and Throttling
For more information about the keywords and options in these commands, see the command reference
for this release.
Configuring IGMP Filtering and Throttling
In some environments, for example, metropolitan or multiple-dwelling unit (MDU) installations, you
might want to control the set of multicast groups to which a user on a switch port can belong. You can
control the distribution of multicast services, such as IP/TV, based on some type of subscription or
service plan. You might also want to limit the number of multicast groups to which a user on a switch
port can belong.
With the IGMP filtering feature, you can filter multicast joins on a per-port basis by configuring IP
multicast profiles and associating them with individual switch ports. An IGMP profile can contain one
or more multicast groups and specifies whether access to the group is permitted or denied. If an IGMP
profile denying access to a multicast group is applied to a switch port, the IGMP join report requesting
the stream of IP multicast traffic is dropped, and the port is not allowed to receive IP multicast traffic
from that group. If the filtering action permits access to the multicast group, the IGMP report from the
port is forwarded for normal processing. You can also set the maximum number of IGMP groups that a
Layer 2 interface can join.
IGMP filtering controls only group-specific query and membership reports, including join and leave
reports. It does not control general IGMP queries. IGMP filtering has no relationship with the function
that directs the forwarding of IP multicast traffic. The filtering feature operates in the same manner
whether IGMP or MVR is used to forward the multicast traffic.
show ip igmp snooping groups vlan vlan-id
[ip_address | count | dynamic [count] | user
[count]]
Display multicast table information for a multicast VLAN or about a
specific parameter for the VLAN:
•
vlan-id—The VLAN ID range is 1 to 1001 and 1006 to 4094.
•
count—Display the total number of entries for the specified
command options instead of the actual entries.
•
dynamic—Display entries learned through IGMP snooping.
•
ip_address—Display characteristics of the multicast group with the
specified group IP address.
•
user—Display only the user-configured multicast entries.
show ip igmp snooping mrouter [vlan vlan-id]
Display information on dynamically learned and manually configured
multicast router interfaces.
Note
When you enable IGMP snooping, the switch automatically
learns the interface to which a multicast router is connected.
These are dynamically learned interfaces.
(Optional) Enter vlan vlan-id to display information for a single VLAN.
show ip igmp snooping querier [vlan vlan-id]
Display information about the IP address and incoming port for the
most-recently received IGMP query messages in the VLAN.
(Optional) Enter vlan vlan-id to display information for a single VLAN.
Table 18-4
Commands for Displaying IGMP Snooping Information (continued)
Command
Purpose
