The fastest way to get this information first-hand would be to set up a network in an emulator (GNS3, VIRL, PacketTracer, etc). There are hundreds of guides online to do this. Then you could do the same show commands and record the output. Regards, Ray Orsini – CEO Orsini IT, LLC – Technology Consultants VOICE DATA BANDWIDTH SECURITY SUPPORT P: 305.967.6756 x1009 E: ray@orsiniit.com TF: 844.OIT.VOIP 7900 NW 155th Street, Suite 103, Miami Lakes, FL 33016 http://www.orsiniit.com | View My Calendar | View/Pay Your Invoices | View Your Tickets -----Original Message----- From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Reza Motamedi Sent: Wednesday, January 13, 2016 12:36 PM To: nanog@nanog.org Subject: Inferring the location points of traffic exchange between two networks Hi NANOG, I am researcher at the University of Oregon and my question is rather primitive. My research background is in networked systems and Internet measurement so I know how things work in theory. My question is about BGP and what can be inferred from the output of different "show" commands, regarding the point of traffic exchange of two networks with different ASNs. I tried going through the some samples on Juniper and Cisco documentations but I did not get my answer. Consider the following scenario; Say the point of traffic exchange between AS_a and AS_b is in San Francisco and we run "show bgp summary" and "show ip bgp <prefix>"on a BGP router of AS_a in LA. Do we see the peering between AS_a and AS_b in San Francisco using any of the two commands. If yes is there a way to infer that in fact the traffic is not exchanged locally in LA? I think there should be a flag to differentiate records showing iBGP vs eBGP. On the same note, if we issue the commands on a router other than the border router in San Fran, is there any difference in the output of show commands? Now how are things different if we actually run the commands on that gateway router in SF? Best Regards Reza Motamedi (R.M) Graduate Research Fellow Oregon Network Research Group Computer and Information Science University of Oregon