Really, the only problem I have is that I have to reset the router everytime I want to host a dedicated COD server.
I run a dedicated server for me and my friends when we want to play, which isn't very often anymore. I would not leave the server up, just start it each time we wanted to play. Everytime I started the server, no one could see it until I rebooted the router and turn on DMZ. I could immediately turn off DMZ and the server would still be seen. If I turned off the server for an extended period of time though, the next time I wanted to run it I would have to reboot the router and throw it in DMZ again.
The problem has persisted over all firmware updates and unless I am mistaken the same problem happened on my DGL-4300. Regardless of what computer I tried to run the server from, the problem always manifested.
Also, I could not run a UT3 server, period. Googling around many people talked about needing a router with "Full Cone NAT" and there was even a list (old as it may have been) of routers that supported the feature. Bottom line, no amount of tinkering would allow me to run a server.