User's Manual
49-8
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 49  Configuring MSDP
Configuring MSDP
Requesting Source Information from an MSDP Peer
Local RPs can send SA requests and get immediate responses for all active sources for a given group. 
By default, the switch does not send any SA request messages to its MSDP peers when a new member 
joins a group and wants to receive multicast traffic. The new member waits to receive the next periodic 
SA message. 
If you want a new member of a group to learn the active multicast sources in a connected PIM 
sparse-mo
de domain that are sending to a group, configure the switch to send SA request messages to 
the specified MSDP peer when a new member joins a group. The peer replies with the information in its 
SA cache. If the peer does not have a cache configured, this command has no result. Configuring this 
feature reduces join latency but sacrifices memory. 
Beginning in privileged EXEC mode, follow these steps to configure the switch to send SA request 
messag
es to the MSDP peer when a new member joins a group and wants to receive multicast traffic. 
This procedure is optional.
To return to the default setting, use the no ip
 msdp sa-request {ip-address | name} global configuration 
command.
This example shows how to configure the switch to send SA request me
ssages to the MSDP peer 
at 171.69.1.1:
Switch(config)# ip msdp sa-request 171.69.1.1
Controlling Source Information that Your Switch Originates
You can control the multicast source information that originates with your switch:
  • Sources you advertise (based on your sources)
  • Receivers of source information (based on knowing the requestor)
For more information, see the “Red
istributing Sources” section on page 49-9 and the “Filtering 
Source-Active Request Messages” section on page 49-11.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
ip msdp sa-request {ip-address | name} Configure the switch to send SA request messages to the specified 
MSDP peer.
For i
p-address | name, enter the IP address or name of the MSDP peer 
from which the local switch requests SA messages when a new member 
for a group becomes active.
Repeat the command for each MSDP peer tha
t you want to supply with 
SA messages.
Step 3
end Return to privileged EXEC mode.
Step 4
show running-config Verify your entries.
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.










