We rent a server in Czech Republic where our web site is running.
When I trace it from USA, India, Russia or Ukraine everything is working fine, trace log shows that querying reaches the hosting company's router. So the site is very well accessible from all these countries.
However when tracing from Finland querying reaches the node in Czech Republic (xe100-5.RT.STL.PRG.CZ.retn.net [220.127.116.11]) and stops displaying timeouts. I suppose this node has nothing to do with the hosting company. As a result guys in Finland are not able to gaze on our gorgeous web site :)
Two things confound me:
Firstly, tracing from India passes through the very same Czech node, IP addresses do match. However tracing goes further and reaches hosting company's router, which is not the case from Finland. How this could happen?
Secondly, users in Finland carried out tracing from within their corporate network. However, when one of the employees tried it from home, the site was accessible just fine, so I suppose tracing was fine as well.
The worst thing is that helpdesks on both sides point me to each other stating that the problem is beyond their area of responsibility.
I've got reply from RETN who controls RT.STL.PRG.CZ router
As can be seen from our looking glass (http://lg.retn.net/), the next hop after RT.STL.PRG.CZ towards you IP address in Czech Republic would be GW1-HostTelecom.retn.net (18.104.22.168) — AS51248 border.
As can be seen from the second trace, they do not use us to reach the IP address in Finland.
I'd suggest looking into AS1759 for the source of the problem.
*second trace means trace back from the server in CR to the client's IP address in Finland
and now wondering how they come to a conclusion that the AS which successfully transferred traffic can be responsible for the issue while their router that blocked everything is not to blame.
Second question is how I can contact any responsible person pertaining to AS1759, please point me to a common way of translating ASN to email.
Finally, why RETN treats it as a problem that back trace goes via different route? Is it really a symptom of routing issue?