Cisco Systems 3750E Controlling Source Information that Your Switch Forwards, Using a Filter

Chapter 43 Configuring MSDP

Configuring MSDP

Controlling Source Information that Your Switch Forwards

By default, the switch forwards all SA messages it receives to all its MSDP peers. However, you can prevent outgoing messages from being forwarded to a peer by using a filter or by setting a time-to-live (TTL) value. These methods are described in the next sections.

Using a Filter

By creating a filter, you can perform one of these actions:

•Filter all source/group pairs

•Specify an IP extended access list to pass only certain source/group pairs

•Filter based on match criteria in a route map

Beginning in privileged EXEC mode, follow these steps to apply a filter. This procedure is optional.

	Command	Purpose
Step 1 configure terminal		Enter global configuration mode.
Step 2 ip msdp sa-filter out ip-addressname		Filter all SA messages to the specified MSDP peer.
	or	or
	ip msdp sa-filter out {ip-addressname}	To the specified peer, pass only those SA messages that pass the IP
	list access-list-number	extended access list. The range for the extended access-list-number
		is 100 to 199.
		If both the list and the route-mapkeywords are used, all conditions
		must be true to pass any (S,G) pair in outgoing SA messages.
	or	or
		To the specified MSDP peer, pass only those SA messages that meet the
	ip msdp sa-filter out {ip-addressname}
		match criteria in the route map map-tag.
	route-map map-tag	If all match criteria are true, a permit from the route map passes routes
		through the filter. A deny filters routes.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
43-12	OL-9775-02