1. WEIGHT
2. LOCAL_PREF
3. Locally originated via a network or aggregate BGP subcommand, or through redistribution from an IGP.
4. AS_PATH
5. ORIGIN
6. MULTI_EXIT_DISC
7. eBGP over iBGP
8. Prefer the path with the lowest IGP metric to the BGP next hop.
9. Check for Multipath.
10. When both paths are external, prefer the path that was received first (the oldest one).
11. Prefer the route coming from the BGP router with the lowest router ID.
12. If the originator or router ID is the same for multiple paths, prefer the path with the minimum cluster list length.
13. Prefer the path coming from the lowest neighbor address.
Understand that this list is GROSSLY oversimplified. If you want more of an explanation of the individual steps, refer to the following link:
http://www.cisco.com/warp/public/459/25.shtml
That document also provides other information, like why a router might ignore a path, how to customize the selection process, how BGP multipath works, etc.
HTH,
JW
--
Justin White, CCIE #14745, MCSE
whitej@gmx.net
