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Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Chapter 21 Configuring IGMP Snooping and MVR
Configuring MVR
These messages dynamically register for streams of multicast traffic in the multicast VLAN on the
Layer 3 device. Switch B. The access layer switch, Switch A, modifies the forwarding behavior to allow
the traffic to be forwarded from the multicast VLAN to the subscriber port in a different VLAN,
selectively allowing traffic to cross between two VLANs.
IGMP reports are sent to the same IP multicast group address as the multicast data. The Switch A CPU
must capture all IGMP join and leave messages from receiver ports and forward them to the multicast
VLAN of the source (uplink) port, based on the MVR mode.
Configuring MVR
These sections contain this configuration information:
• Default MVR Configuration, page 21-18
• MVR Configuration Guidelines and Limitations, page 21-18
• Configuring MVR Global Parameters, page 21-19
• Configuring MVR on Access Ports, page 21-20
• Configuring MVR on Trunk Ports, page 21-22

Default MVR Configuration

Table 21-5 shows the default MVR configuration.

MVR Configuration Guidelines and Limitations

Follow these guidelines when configuring MVR:
• Receiver ports on a switch can be in different VLANs, but they should not belong to the multicast
VLAN.
• In Cisco IOS Release 12.2(25)SEG and earlier, only access ports could be configured as MVR
receiver ports. In Cisco IOS Release 12.2(35)SE and later, trunk ports can also be configured as
receiver ports.
• The maximum number of multicast entries (MVR group addresses) that can be configured on a
switch (that is, the maximum number of television channels that can be received) is 512.
Tab le 21-5 Default MVR Configuration
Feature Default Setting
MVR Disabled globally and per interface
Multicast addresses None configured
Query response time 0.5 second
Multicast VLAN VLAN 1
Mode Compatible
Interface (per port) default Neither a receiver nor a source port
Immediate Leave Disabled on all ports