Firstly, Make sure you have a router of some sort in your house. Try to get a wired connection to your PS3, as wifi has lag, and lag is bad. Once you do this, log into your router from one of your computers that are connected to that router. (Each router is different, but if I don’t have the information here, then please comment me, and I will respond with whatever I can to help you.) Once in the router you need to see what the ip pool is for dynamically assigned clients. What this is is that whenever a computer, or unit connects to the router it automatically gets a ip number that the router wants that unit to have. Pick a number in the range up to 255 that you would like to use. You will also need to have the DNS server numbers from the router. They will usually be on the administration, or status page.
Example: Router is 192.168.1.1 – Dynamically assigns numbers 192.168.1.2 through 192.168.1.50 – You would choose any number after 50, but before 255. The beginning the segments must remain the same.
After accomplishing this, go into PS3 system setup, and go to the network settings. Make a CUSTOM configuration. Enter in your routers ip number, the subnet mask, & DNS servers. On one of the screens you will be asked to enter the ip for the PS3. Enter the number you chose. Enter in any other information. When you are finished, allow the test. Everything should pass if you did this all correct.
Most people will also put their PS3 in the DMZ zone. The DMZ zone is a ip that is allowed to recieve anything sent to it without filtering, and such other roadblocks.
Below is a video of the entire process…
This person does an automatic ip addressing, and this is fine, but manual addressing is best.
This video is for setup with a wireless connection…