3.7.c Explain attributes and best-path selection

it never goes away… from http://insearchofthecert.blogspot.com/2012/10/bgp-attribute-precedence-quote-of-day.html

  • Highest weight (Cisco-proprietary BGP value)
  • Highest local preference (LOCAL_PREF)
  • Prefer locally originated route.
  • Shortest AS_PATH is preferred.
  • Choose route with lowest origin code. Internal paths are preferred over external paths, and external paths are preferred over paths with an origin of “incomplete”.
  • Lowest multi-exit discriminator (MED)
  • External BGP routes preferred over Internal BGP routes.
  • If no external route, select path with lowest IGP cost to the next-hop router for iBGP.
  • Choose oldest (most stable)
  • Choose lowest BGP RID (Router ID).