i assume you want this for ftp? i use ps3 ethernet to laptop ethernet connections... goto your control panel/network and internet/click network and sharing center/on left choose Change adapter settings.. then plugin your ethernet cable into your laptop/pc from your ps3 and switch on your ps3.
you should see your ps3 pop up in the list highlight this and hightlight your pc connection... make sure both highlighted and right click one of them and choose bridge connections... then restart laptop/pc... and ps3 and goto your ps3 and see if you have a ip address. if you do open gaia/multiman and enable ftp... should se your ip its 192.168.1.xx or something.
if you using filezilla open it up put that ip in no user no pass and and hit enter... think thats the way i did it and when i ftp its transfers at 13-15mbs steady... don't know if this helps.. i'm using win7... it worked for me.. good luck!
also on ps3 goto network settings and go through internet/connection setup!!! to get a new or diff ip address... just to refresh connection status.