Is traffic leaving and arriving through the same provider? Sounds similar to a Reverse Path Forwarding issue I had a long time ago.
Chris Wright Network Administrator From: Af [mailto:af-boun...@afmug.com] On Behalf Of Steve Jones Sent: Wednesday, August 23, 2017 9:59 AM To: af@afmug.com Subject: [AFMUG] help understanding and troubleshooting bgp from the target perspective we have been dealing with amazon issues on one of our upstreams they had some BGP issues where they werent sending our announcements to the world, watching the peering all of a sudden they were peered with level3 directly, our announcements were working but we started having skullduggery with amazon and images, im guessing either AWS hosted or in a similar locale moving them to our other provider (ended up terminating our peering session) and all was resolved I have figured out how to poke around in looking glasses and that to get general paths, but with the whole distributed hosting and geolocation dns or whatever, how do i get to a point where i can discover what actual server theyre getting to and then be able to find out what our ASN looks like from their perspective? I think this was an asynchronous path in which one of the directions was horrible basic testing, just to the IP resolving to amazon.com each provider path showed a different IP in resolution using the same DNS servers, which is odd, i guess, we just run bind recursive with no geo magician .voodoo. the problem provider had huge latency to both IPs the other was good, from our ASN Now hitting the same IP from our edge router, presenting as our provider IP space the path was different but clean, I asssume thats their internal routing or something. long story short, without knowing an engineer at amazon, (or any other target) is there a way to see the path back to our ASN?
