44-37
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
OL-12247-01
Chapter 44 Configuring IP Multicast Routing
Configuring Optional Multicast Routing Features
To disable CGMP on the interface, use the no ip cgmp interface configuration command.
When multiple Cisco CGMP-capable devices are connected to a switched network and the ip cgmp
proxy command is needed, we recommend that all devices be configured with the same CGMP option
and have precedence for becoming the IGMP querier over non-Cisco routers.
Configuring sdr Listener Support
The MBONE is the small subset of Internet routers and hosts that are interconnected and capable of
forwarding IP multicast traffic. Other multimedia content is often broadcast over the MBONE. Before
you can join a multimedia session, you need to know what multicast group address and port are being
used for the session, when the session is going to be active, and what sort of applications (audio, video,
and so forth) are required on your workstation. The MBONE Session Directory Version 2 (sdr) tool
provides this information. This freeware application can be downloaded from several sites on the World
Wide Web, one of which is http://www.video.ja.net/mice/index.html.
SDR is a multicast application that listens to a well-known multicast group address and port for Session
Announcement Protocol (SAP) multicast packets from SAP clients, which announce their conference
sessions. These SAP packets contain a session description, the time the session is active, its IP multicast
group addresses, media format, contact person, and other information about the advertised multimedia
session. The information in the SAP packet is displayed in the SDR Session Announcement window.
Step 3
ip cgmp [proxy]
Enable CGMP on the interface.
By default, CGMP is disabled on all interfaces.
Enabling CGMP triggers a CGMP join message. Enable CGMP only on
Layer 3 interfaces connected to Layer 2 Catalyst switches.
(Optional) When you enter the proxy keyword, the CGMP proxy function
is enabled. The proxy router advertises the existence of
non-CGMP-capable routers by sending a CGMP join message with the
non-CGMP-capable router MAC address and a group address
of 0000.0000.0000.
Note
To perform CGMP proxy, the switch must be the IGMP querier. If
you configure the ip cgmp proxy command, you must manipulate
the IP addresses so that the switch is the IGMP querier, which
might be the highest or lowest IP address, depending on which
version of IGMP is running on the network. An IGMP Version 2
querier is selected based on the lowest IP address on the interface.
An IGMP Version 1 querier is selected based on the multicast
routing protocol used on the interface.
Step 4
end
Return to privileged EXEC mode.
Step 5
show running-config
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Step 7
Verify the Layer 2 Catalyst switch CGMP-client configuration. For more
information, see the documentation that shipped with the product.
Command
Purpose
