Routers R1 nad R2 are connected through the serial HDLC line. R1 router is a BGP speaker running AS 200, the R2 router is an AS100 BGP speaker. Both routers are configured with correct BGP neighbor commands to form an eBGP peering. The capture is displaying the moment when we activate serial interconnecting interface (no shutdown) of the R2 router.
Capture displays the initial TWH TCP handshake required for BGP session (port179, BGP Connect state) and the exchange of Open BGP messages (moving from Connect to Open sent state) emitted by the R2 router for its neighbor (R1 here). The R1 router sent its own BGP Open message, both routers agrree on provided parameteres and are moving to Open confirm BGP state sending theirs BGP Keepalive messages.
Number of packets: 7