BGP

Annotations:

• https://tools.ietf.org/html/rfc4271

1. BGP State Machine
2. TCP port 179

   Annotations:

   • BGP uses TCP [RFC793] as its transport protocol. This eliminates the need to implement explicit update fragmentation, retransmission,acknowledgement, and sequencing. BGP listens on TCP port 179. The error notification mechanism used in BGP assumes that TCP supports a"graceful" close (i.e., that all outstanding data will be delivered before the connection is closed).
3. iBGP eBGP
   1. iBGP

      Annotations:

      • AD 220 Keeps nextp-hop
   2. eBGP

      Annotations:

      • AD 20 Changes next hop