Configuring MSDP Using a Filter Command or Action Purpose Device#configure terminal Step 3 Use one of the following: • ip msdp sa-filter out { ip-address name } • ip msdp sa-filter out { ip-address name } list access-list-number • ip msdp sa-filter out { ip-address name } route-map map-tag Example: Device(config)#ip msdp sa-filter out switch.cisco.com or Device(config)#ip msdp sa-filter out list 100 or Device(config)#ip msdp sa-filter out switch.cisco.com route-map 22 • Filters all SA messages to the specified MSDP peer. • Passes only those SA messages that pass the IP extended access list to the specified peer. The range for the extended access-list-number is 100 to 199.
If both the list and the route-map keywords are used, all conditions must be true to pass any (S,G) pair in outgoing SA messages. • Passes only those SA messages that meet the match criteria in the route map map-tag to the specified MSDP peer. If all match criteria are true, a permit from the route map passes routes through the filter. A deny filters routes. Step 4 access-list access-list-number {deny | permit} protocol source source-wildcard destination destination-wildcard Example: Device(config)#access list 100 permit ip 194.1.22.0 1.1.1.1 194.3.44.0 1.1.1.1 (Optional) Creates an IP extended access list, repeating the command as many times as necessary.
• For access-list-number, enter the number specified in Step 2. • The deny keyword denies access if the conditions are matched. The permit keyword permits access if the conditions are matched. • For protocol, enter ip as the protocol name. • For source, enter the number of the network or host from which the packet is being sent. • For source-wildcard, enter the wildcard bits in dotted decimal notation to be applied to the source. Place ones in the bit positions that you want to ignore. Configuring MSDP 14