Cisco 4500M User Manual

18-16
Software Configuration Guide—Release 12.2(25)EW
OL-6696-01
Chapter 18 Configuring IGMP Snooping and Filtering
Configuring IGMP Filtering
This example shows how to display IGMP snooping information on VLAN 5:
Switch#show ip igmp snooping vlan 5
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping :Enabled
IGMPv3 snooping support :Full
Report suppression :Enabled
TCN solicit query :Disabled
TCN flood query count :2
Vlan 5:
--------
IGMP snooping :Enabled
Immediate leave :Disabled
Explicit Host Tracking :Disabled
Multicast router learning mode :pim-dvmrp
CGMP interoperability mode :IGMP_ONLY
Configuring IGMP Filtering
This section includes the following subsections:
• Default IGMP Filtering Configuration, page 18-17
• Configuring IGMP Profiles, page 18-17
• Applying IGMP Profiles, page 18-18
• Setting the Maximum Number of IGMP Groups, page 18-19
Note The IGMP filtering feature works for IGMPv1 and IGMPv2 only.
In some environments, for example metropolitan or multiple-dwelling unit (MDU) installations, an
administrator might want to control the multicast groups to which a user on a switch port can belong.
This allows the administrator to control the distribution of multicast services, such as IP/TV, based on
some type of subscription or service plan.
With the IGMP filtering feature, an administrator can exert this type of control. With this 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.
IGMP filtering controls only IGMP membership join reports and has no relationship to the function that
directs the forwarding of IP multicast traffic.
You can also set the maximum number of IGMP groups that a Layer 2 interface can join with the
ip igmp max-groups <n> command.

Cisco 4500M Specifications

General

Brand	Cisco
Model	4500M
Category	Network Router
Language	English