Larry_OHF Also try this link
http://nwn.bioware.com/support/techfaq.html#03.
It says
1.03: How can I play through a Firewall? (Back to Top)
If you are trying to play through a firewall of some sort, here is some information for you to help you get connected. Neverwinter Nights uses UDP, not TCP for its connections. If you think that your firewall is preventing you from connecting to the game servers, please make sure that the following ports are open:
Ports 5120 through 5300
Port 6500
Port 27900
Port 28900
In addition to opening the ports listed above, you may need to allow incoming connections on the port you are running your server on (5121 by default) and forward those connections to the computer running the server.
If you have multiple computers behind a firewall and you want to play multiplayer with 2 or more of them at the same time, you must ensure the Client Port setting for each computer is set to a different value. You will find this entry in the file nwnplayer.ini Simply double click on it to open it, and look for the Client Port= line in the [Profile] section. Change this from the default value of 5120 on each machine. You have to stay in a certain range, so use numbers like 5121, 5122, 5123, etc.
If your server does not appear on the GameSpy game list:
Verify that it is does not appear for other users. It may not be appearing for you because your game is published by your external IP address, this address may not be valid from inside your firewall.
Verify that the server is accessible from the Internet, have a friend Direct Connect using your external IP address (ie not 127.0.0.1 or 192.168.*.*, these are local addresses).
If you are starting your module from the command line of the Windows or Linux dedicated server, try starting it from within the application.
If your module is very large or contains very large areas, try breaking it up into smaller pieces.
If you are wanting to make sure that your NAT is set up to allow the game to play here are some details.
Outgoing packets
Source port: 5120-5129
Destination port: 5121-5300
Incoming packets
Source port: 5121-5300
Destination port: 5120-5129
On the Game Client side, here are some changes to make things go better. Go to your nwnplayer.ini file in your Neverwinter Nights install directory, and find the following section:
[Profile]
Client Port=XXXX
Our suggestion is to change XXXX to 5120.
I hope this helps,
Granamere