Hi,
DNS is Domain Name Service. It is usually your router that looks after the when you are at home but you can set servers u to do it.
When you connect to your ISP you have a gateway address which is the address given to you by your ISP, then your home router (i thats what you use) creates a secondary ntwork which is more than likely 192.168.0.1 although the last to numbers may vary.
So when you are at home your computer may have an IP of 192.168.1.22 and when you go on the internet that is exchanged by your router for you actuall IP address
a tip for you is to go into the admin section of your router and allocate the MAC address of your PSP a Static IP address, then goto into the settngs of your PSP and enter the same IP. this should then work.
Good lick and hope I made sense (I have had a little to drink

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