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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter46 Configuring IP Multicast Routing
Configuring Optional Multicast Routing Features
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.
Enabling sdr Listener Support
By default, the switch does not listen to session directory advertisements.
Beginning in privileged EXEC mode, follow these steps to enable the switch to join the default session
directory group (224.2.127.254) on the interface and listen to session directory advertisements. This
procedure is optional.
To disable sdr support, use the no ip sdr listen interface configuration command.
Limiting How Long an sdr Cache Entry Exists
By default, entries are never deleted from the sdr cache. You can limit how long the entry remains active
so that if a source stops advertising SAP information, old advertisements are not needlessly kept.
Beginning in privileged EXEC mode, follow these steps to limit how long an sdr cache entry stays active
in the cache. This procedure is optional.
To return to the default setting, use the no ip sdr cache-timeout global configuration command. To
delete the entire cache, use the clear ip sdr privileged EXEC command.
To display the session directory cache, use the show ip sdr privileged EXEC command.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify the interface to be enabled for sdr, and enter interface
configuration mode.
Step3 ip sdr listen Enable sdr listener support.
Step4 end Return to privileged EXEC mode.
Step5 show running-config Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 ip sdr cache-timeout minutes Limit how long an sdr cache entry stays active in the cache.
By default, entries are never deleted from the cache.
For minutes, the range is 1 to 4294967295.
Step3 end Return to privileged EXEC mode.
Step4 show running-config Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.