In light of the up and coming douche move by Sony removing OtherOS support from the PS3 in their upcoming 3.21 firmware update.
For those who do not wish to update I am writing a quick how-to on blocking PSN without having to unplug it from the net or disabling wifi all together. If you're like me and dont use PSN to play games online but still need it to function with your media server to use it for the awesome media player that it is AND keep the OtherOS function that you paid for... this is the guide for you!
For the savvy all you need to do is manually set the DNS servers to some random IP. I used 22.214.171.124 for the primary and 126.96.36.199 for the secondary. For the not so savvy follow these quick steps..
First we will gather some info you will need.
1. Via XMB goto Settings -> Network Settings -> Settings and Connection Status List. A list with some numbers and other info will pop up.
2. Write down the #'s next to IP address, Subnet Mask and Default Router.
Next we will make the changes needed to block PSN (Sony)
1. Via XMB goto Settings -> Network Settings -> Internet Connection Settings
2. A message will pop up - "Adjust settings for connection to the Internet.. blah blah blah" press OK
3. Select 'Custom' as the setting method.
4. If using a wired connection select it. You will come to "Select operation mode for network device". for most Auto-Detect works just fine.
If you are using a wireless connection you will need to select that then proceed to enter the info to login to your wireless router.
Either way you will come to a screen labeled "IP Address Setting".. now go onto step 5.
5. On the "IP Address Setting" screen you want to select Manual. This is where you will input the info we wrote down from the first steps. When you get to primary and secondary DNS you will want to input a bogus DNS server. Odds are anything you randomly put in will do (unless you get lucky and guess an actual DNS server=P). But I used 188.8.131.52 for both. Once you have entered the info you can move onto the next screen.
6. Next you will come to a screen labeled "MTU" if you are using this guide odds are that you need to select Automatic.
7. The next screen is for setting up a proxy server.. if you use one set it up if not or you don't know what a proxy server is then just select Do No Use.
8. The next screen is "UPnP".. odds are you need to select Enable.
9. The last screen will ask you to press the 'X' button to save. So.. Hit 'X'!
10. The last screen says "Save Completed." if you are sure you have done it correctly you can just press 'O' and your back to the XMB menu . If you are unsure you did it correctly run the "Test Connection". It should succeed in obtaining an IP address and after a minute or so it will fail on the internet connection. If it does you have officially cut the umbilical cord to Sony/PSN.
11. While not necessary i suggest rebooting your PS3 to ensure the settings have stayed. Upon reboot you will not be able to login or access PSN in any way. If you can you did not do something right so try again =P
*note - unfortunately for some you also will not be able to use the XMB's web browser.. If you actually have an OtherOS installed i hope you never use it anyways! it sucks! if you dont have Linux installed on your ps3 I suggest you do so, if only to use a real web browser!
A good guide to getting Ubuntu up and running can be found at psubuntu.com.. while there are some guides on the official PS web site i would assume they will be taking them down soon.