An answer I found you can try :
Go into the multiplayer menu.
(pro-tip, the master authorization server was taken down, so add the following two entries into your hosts file "/windows/system32/drivers/etc/hosts"
and instead of waiting 2 minutes for the time out, it will time out instantly)
If you are hosting, New game (or load game for subsequent play throughs) just set up your server once, and it keeps the settings from then on.
To join, just use the direct connect button, and type in the IP directly. No virtual LAN required."
I remember I had problems too, but you can try to launch the game after disabled your firewall (windows or an other) sometimes it helps.
nw2master.bioware.com and nwn2.master.gamespy.com is for nwn 2. For the orignial nwn you need the following two lines (of course you could put in all 4):