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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
OL-9639-06
Chapter 21 Configuring IGMP Snooping and MVR Understanding Multicast VLAN Registration
For more information about the keywords and options in these commands, see the command reference
for this release.
Understanding Multicast VLAN Registration
Multicast VLAN Registration (MVR) is designed for applications using wide-scale deployment of
multicast traffic across an Ethernet ring-based service-provider network (for example, the broadcast of
multiple television channels over a service-provider network). MVR allows a subscriber on a port to
subscribe and unsubscribe to a multicast stream on the network-wide multicast VLAN. It allows the
single multicast VLAN to be shared in the network while subscribers remain in separate VLANs. MVR
provides the ability to continuously send multicast streams in the multicast VLAN, but to isolate the
streams from the subscriber VLANs for bandwidth and security reasons.
MVR assumes that subscriber ports subscribe and unsubscribe (join and leave) these multicast streams
by sending out IGMP join and leave messages. These messages can originate from an IGMP
Version-2-compatible host with an Ethernet connection. Although MVR operates on the underlying
mechanism of IGMP snooping, the two features operate independently of each other. One can be enabled
or disabled without affecting the behavior of the other feature. However, if IGMP snooping and MVR
are both enabled, MVR reacts only to join and leave messages from multicast groups configured under
MVR. Join and leave messages from all other multicast groups are managed by IGMP snooping.
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.
show ip igmp snooping querier [vlan vlan-id]
detail Display information about the IP address and incoming port of the
most-recently received IGMP query message in the VLAN,and the
configuration and operational state of the IGMP snooping querier in the
VLAN.
Table 21-4 Commands for Displaying IGMP Snooping Information (continued)
Command Purpose