Cisco Catalyst 2960 Series, Configuration Manual

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Default Setting Feature
Disabled TCN query solicitation
Disabled IGMP snooping querier
Enabled IGMP report suppression
1 (1) TCN = Topology Change Notification
Related Topics
Enabling or Disabling IGMP Snooping on a Switch , on page 128
Enabling or Disabling IGMP Snooping on a VLAN Interface, on page 129
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.
These sections describe MVR:
MVR and IGMP
MVR can coexist with IGMP snooping on a switch. Note
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 method 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.
The switch CPU identifies the MVR IP multicast streams and their associated IP multicast group in the switch
forwarding table, intercepts the IGMP messages, and modifies the forwarding table to include or remove the
subscriber as a receiver of the multicast stream, even though the receivers might be in a different VLAN from
the source. This forwarding behavior selectively allows traffic to cross between different VLANs.
Modes of Operation
You can set the switch for compatible or dynamic mode of MVR operation:
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Information About IGMP Snooping and MVR