BGP states and TCP

[mozmarr124]

Hi, struggling to see at what stage TCP fits into the overall BGP state process. I know it's the first thing that happens, but does it come before Idle or before Active for example or does it function alongside these and how?

In essence, where does TCP fit in in the state process - also is it continuous through the state process or does it stop at one of the states?

 <<< TCP here?

IDLE  <<< TCP here?

CONNECT <<< TCP here?

ACTIVE <<< TCP here?

OPENSENT

OPENCONFIRM

ESTABLISHED

Ive looked at plenty of documents but still struggling....

[Meheretab Mengistu]

Hi Stephen,

One way to understand BGP and TCP relationship is to think BGP as an application using TCP as a transport layer protocol like HTTP. BGP always needs and relies on TCP for transport (port 179). When you configure BGP process on a router and when it starts sending packets related with BGP, it uses TCP. Any BGP packet is on TCP.

HTH,
Meheretab