January 16, 2011

BGP

RFC1771 – you have control only over your AS, you cannt tell other AS how to route traffic passing through (attributes).

Neighbor relationship;

  • Neighbors start in IDLE
  • 1st Stage: ACTIVE
  • 2nd Stage: OPEN SENT
  • 3rd Stage: OPEN CONFIRMED
  • 4th Stage: ESSTABLISHED

Hello messages sent every 60 sec and holddown timer as 180 sec

Authentication is MD5

Rule of syncronisation – Routes learnt by BGP must be validated by the interior routing table before they can be advertised to remote peers.

BGP SPlit Horizon – Routes learned via iBGP will never be sent to another iBGP peer (this is where route reflectors come into play).