The ISP I am using really works perfectly well, they fulfill their SLA perfectly. I have nothing to complain at all. Of course you can, well you can't but the ISP you are getting the connectivity from can: * Monitoring their network * Having multiple upstreams. And as COLT is one of those known problematic providers, I have nothing else to say there but: call them and let them fix their network. Because the packets can't get back to you, welcome to the wonderful world of the Internet which uses BGP and thus sometimes asymetric paths for routing. This sounds more like filtering port 80 on your machine and saying then blaming the ISP's that websites don't work. What do you expect then? That we are going to call your ISP and resolve your problems while it is not our problem? If it really was a SixXS problem, why didn't you contact the SixXS Staff and notified them of this issue? You did notice the "If you want to ask a question to the SixXS Staff, either operational issues, abuse and/or other questions, then these should be directed to the contact address. The SixXS Staff don't regulary browse the forums, thus if you want to ask them something use the contact address." notice when you posted onto the forum I hope? Next to that we are indeed promoting IPv6, even though we don't make advertisements etc. But your issue is an IPv4 (read again, there is a 4 there, not a 6) issue and it has nothing to do with any of the networks that provides POPs to SixXS. It would be the same as a user in japan complaining that somewhere between tokio and los angeles a route is failing causing him not to be able to connect to SixXS website, unfortunatly we cannot do anything about those problems.