[quote name='Teh Nitwit']Thanks for the response

. It was hard to find answers to this because it would seem that not that many people try to do LAN games with their PS3s. Your answer has been very helpful.
I was reading topics on this
board and also the bottom of this
page on the PS3 manual mentioned that uPnP might be required for LAN.
Still, one thing is not clear to me. I was getting NAT3 before I forwarded all those ports to the PS3s (I know, I was doing it wrong - a port can be forwarded to only 1 address). After I forwarded them, I got NAT2. This leads me to believe that the ports were not "open" (although I could play worhawk online just fine

?). Also, that official manual page mentions that port UDP: 3658 is used for direct communication with other PS3s. If that port is not open in my router by default, then how could I make both PS3s be able to communicate over it without forwarding?
I guess I am wondering if there is a way to simply "open" a port to make it available to all devices connected to the router. I will check this when I get home. Also, doesn't DMZ mean that all unrecognized traffic would be sent to the IP address in the DMZ? Are you suggesting that it might work if I forward all the ports to one PS3 and put the other in DMZ?
Thanks again mguiddy, and if you or anyone else feels like answering my stupid questions I will be eternally grateful

.[/quote]
Well Nat 2 is what you want to get, it means that the ports were forwarded. Nat 1 is if you had the firewall off on the router (I think that would do it) or if you had it wired directly into the modem.
I don't think there is a way to open a port to all devices, but I'm no expert.
I don't think "all unrecognized traffic" (as in your router going "What's this...? Well I'll just send it to the DMZ.

") is sent to the DMZ, just that devices in the DMZ are considered not to be behind a firewall.
It should work if you forward the ports to one PS3 and put the other in the DMZ.
Though before you try all this hassle, you may only need the ports open to the server for it to work.