MSDP Anycast-RP RPF query

[phillipadams_tns]

Hi, I seem to find conflicting information regarding the RPF check on MSPD peerings. Some documents say that you must run BGP for the RPF checks to be successful. You can bypass this neccessity by adding the command 'ip msdp peer rpf rfc3618'. see link:

http://www.cisco.com/en/US/products/ps6922/products_feature_guide09186a00801d1d1c.html

However, I have been able to successfully get a MSDP Anycast-RP setup to work in a lab environment by only using Eigrp. all three devices that make up the peering relationship learn each others sources. Note, I havent used mesh-groups or MSDP default peers.

Has anyone got any ideas as to why this document says it can only work one way, when I am able to get it to work differently.

Thanks

[mark.edwards]

Hi, I'm no expert when it comes to MSDP but did study it for CCIE. From memory you can use BGP or IGP for RPF check. When using Anycast you would normally use IGP for RPF as the loopback address (which is the same IP address on 2 routers) is advertised into your IGP. Using MSDP and BGP for RPF check is more likely to be used between ISP's when they don't share a IGP. This is not "Anycast" but standard MSDP.

BGP Example

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a00800ca797.html#wp1001303

Anycast Example

http://www.cisco.com/en/US/tech/tk828/technologies_white_paper09186a00800d6b60.shtml