I have a very strange situation on a Linux (CentOS) server.
Firstly, from my Ubuntu desktop PC, I can successfully connect to all services that are running on it, on ports 22, 80, 8080 and others. Ping also works and reports a latency of 20 ms, though it takes longer than 20 ms before it shows that.
Not everywhere though. From several servers around the world:
- I cannot connect at all to services running on TCP ports like 8080 and 23011.
- If I
wget server.domain.com:80I get a 403 forbidden, while from my client that also works fine. However,
wget server.domain.com:80/somedirworks fine.
pingsays "Destination Port Unreachable".
- I don't think the location of the server matters; I can't even connect from another server that is in the same building (I think, not sure)
- The servers that can't connect don't themselves have restrictive firewall or proxies.
I thought it might be something firewally, but this is
Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
Looks empty to me.
I checked whether maybe the other server were somehow connecting to a different server (because of a DNS thing or duplicate IP or something), but that's not the case. The IP is the same everywhere and I can
wget a html page that I know to be mine.
What can be up?
(Sorry if there is some information missing. I have root access to this server, but I'm not really its admin. I'm a programmer, not a professional server admin)