Unable to Receive External Connections

Hey Folks,

Here's the problem. I'm running XP SP2 on my PC and I've got my mud in a cygwin environment. The time has come to get some people helping to build/test but no one outside my router can connect. I'm behind a Linksys WRT54GC ver. 2.0 with port forwarding on port 5003, TCP enabled. I have also made the necessary exception/open port in the windows firewall. I can connect to my server by localhost and/or 127.0.0.1 and I am also able to connect using my external IP and/or host name as listed by ipconfig. When I run Microsoft's port query 2.0 I get the following:

Querying target system called:
127.0.0.1
Attempting to resolve IP address to a name...
IP address resolved to localhost
querying...
TCP port 5003 (unknown service): LISTENING

Querying target system called:
x.x.x.x [my external ip]
Attempting to resolve IP address to a name...
IP address resolved to [my host]
querying...
TCP port 5003 (unknown service): LISTENING

However, when I do a port scan at http://www.t1shopper.com/tools/port-scanner/ I get this:
Scanning ports on x.x.x.x (host)
x.x.x.x isn't responding on port 23 (telnet).
x.x.x.x isn't responding on port 5003 ().
The external IP responds to pings normally but the port doesn't accept connections. I've tried varying the port number with no change. I do not believe the problem is with the XP firewall because I've tried disabling it completely and nothing changes. I also do not believe this is a problem with port forwarding because when I disable it I am no longer able to connect through my external IP or host. I've also tried TCP, UDP and both. Most recently, I removed the router and took the wire directly from the wall to my PC/server. This also changes nothing. I'm a novice when it comes to networking but I've put a lot of time in and I really want to solve this. Cheers.

-ryan

Are you sure that your external IP is actually an external IP? You might be behind another router at the ISP level, so that your IP is in fact only good for other people behind that router, and not the whole world.

If you have another computer, one test would be to put it behind the same router as the one with the server, and try the 'external IP' and see if it works.

Hey Dave,

Thanks for the reply. I tried connecting from the comp in my buddy's room down the hall and it worked. This lends evidence to the ISP NAT router theory. Is there a work-around or am I fubared? I'd prefer not to pay for hosting, I'm just beginning development. Cheers.

-Ryan

There are some free hosts out there.

Also, check out dslreports.com, see if any of the tests there can help.

When you did the port forwarding on the router, did you also open the port in the router's firewall?

I'm not talking about the XP firewall, I'm talking about the firewall rules built into the router.