Have you googled it!

It's DNS error which means your router is having a hard time sorting IP address' for devices usually a cold boot to the PS3 and Router solves it wait 20 secs before turning router back on once its dialled out boot up the PS3 and then try it. But if not do this what it says in the link 1) Leave your PS3 settings on automatic/easy (probably what you already had it set as before). 2) Locate the IP address of your router. For example’s sake, mine is a D-Link DI-604 with IP 192.168.0.1 3) Open a web browser (Firefox or Internet Explorer for example) on a computer connected to your router (The PS3’s browser might also work but I didn’t try that). 4) In the address bar, type in the IP address of you router. 5) If it asks for a username and password, enter whatever you set it as. If you never set one, check the manual with your router and it will probably give the default username and password. If you can’t find one, try username “admin” with no password. 6) Once you get in, look for the setting to enter "DNS Primary and Secondary." (In mine, it was under “WAN.”) Once you find it, enter the values above for DNS (208.67.222.222 primary and 208.67.220.220 secondary). - Mine had 0.0.0.0 for both primary and secondary before I did this which makes me further believe that this was the problem. - Make sure to apply the changes. 7) Check the connection on your PS3 and hope that it is working. By the way what router are you using that also helps to provide that info and does it have the latest Firmware update to it usually they say never to update if it works fine but I find updating such things fixes other faults you may come up with later on I do update my NetGear DG834GT router when a new 1 comes out.