1) First you need to find your routers "default gateway". On your computer go to "run" in the start menu and type in "cmd". Type in "ipconfig" and look for "default gateway". Note down the numbers.
2) Now go on ur ps3, go to Settings > Network Settings > Internet Connection Settings" option on the PS3 Cross bar menus. Select "Wired" or Wireless" (choose the one that refers to you). Both selections should show a page called "Address Settings". Here you will need to select "Custom". Another page will then display entitled "IP Address Setting". The option "Manual" will need to be selected. Now a page of customizable ip addresses can be entered. This is the important part...
Ip address - This will need the static ip internal address. Just enter something like 192.168.1.100 as it is unlikely 99 other devices are connected to the same system. (By the way u can just use 192.168.1.100 for the static ip if u want...it really doesn't matter)
Subnet Mask - Is always set to 255.255.255.0
Default router - now enter the "default gateway" address you got earlier from your computer
Primary DNS - Same IP Address as "Default Router"
Secondary DNS - Same IP Address as "Default Router"
Select "Enter" and a "MTU" screen should come up (i dont know what the hell MTU is). Just select "automatic" and then select "Do not use proxy" on the next screen.
3) Now go back on your PC, open your web browser and enter that "default gateway" address into the address bar. A login authorization prompt may come up and you will need to enter your username and password (should be somewhere in the user manuel for the router). If your using a linksys router like me leave the username box empty and enter "admin" for the password.
4) A router configuration page should show up showing many settings and options you will have no clue about (note that all router configuration interfaces are different depending on the make of the router, so the settings/preferences will be in different places). All your interested in is finding a setting named as "DMZ" of anything with "DMZ" in it. So search around in all the tabs and settings for the mention of "DMZ" (it might be in your security/firewall settings). One you have found it, there should be an option of enabling it. Do so and then enter the static ip address you gave your ps3 earlier; the example i gave was 192.168.1.100. So enter that and select "apply" or "save changes". Whilst your on there try and find a setting of "UPNP" and make sure thats enabled aswell.
5) Now turn off everything running on your router including the router, computers, ps3 etc This is done so the changes can take place asap. Wait a few minutes and then turn everything back on and the process is complete. You should realise that the light below the DMZ option on the router should have lit up and do an "Internet connection test" on your ps3. You should get UPNP available and NAT type 2
