neither ulti nor mr.nightfire are right, .1 is the router, not the local ip, and ulti, it's just a description, not program's name, and it's controlled by the router, not by Firewall software.
cheak to see if firewall is blocking it, or even your router as I have got a netgear router and you have to set up firewall rules with it too.
also another simple problem, you have to set the server up normmaly first.
make sure that in the multiplayer menu in nightfire it have the tick in the internet circle box thing not the LAN circle box. if its in the lan circle box, run the server with the tick in the internet box to chanage setings, then once its loaded quit nightfire and open uup dss.