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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter23 Configuring IGMP Snooping and M VR Understanding Multicast VLAN Registration
Using MVR in a Multicast Television Application
In a multicast television application, a server connected to a blade switch can receive the multicast
stream. Multiple devices can be connected to one subscriber port, which is a switch port configured as
an MVR receiver port. Figure 23-3 is an example configuration. DHCP assigns an IP address to the
server. When a subscriber on the server selects a channel, the server sends an IGMP report to the blade
switch to join the appropriate multicast. If the IGMP report matches one of the configured IP multicast
group addresses, the switch CPU modifies the hardware address tabl e t o i nc lude this re ce iver port and
VLAN as a forwarding destination of the specified multicast stream when it is received from the
multicast VLAN. Uplink ports that send and receive multicast data to and from the multicast VLAN are
called MVR source ports.
Figure23-3 Multicast VLAN Registration Example
When the subscriber changes channels or stops the multicast stream, the server sends an IGMP leave
message for the multicast stream. The switch CPU sends a MAC-based general query through the
receiver port VLAN. If there is another device in the VLAN still subscribing to this group, that device
must respond within the maximum response time specified in the query. If the CPU does not receive a
response, it eliminates the receiver ports as a forwarding destination for this group.
Without Immediate Leave, when the switch receives an IGMP leave message from a subscriber on a
receiver port, it sends out an IGMP query on that port and waits for IGMP group membership reports. If
no reports are received in a configured time period, the receiver port is re moved from mu l tica st group
membership. With Immediate Leave, an IGMP query is not sent from the re ce iver port on whi ch t he
Multicast VLAN
SP
SP
SP
SP
RP1 RP2 RP3 RP4 RP5
RP = Receiver Port
SP = Source Port
Note: All source ports belong to
the multicast VLAN.
SP
Cisco router
Multicast
server
Server
Switch
Blade Switch
Switch Switch
201915
ServerServer ServerServer