I have hardware ethernet loopback, but when I plug it in ethernet still say no media. I have VAIO VPCY11S1E with windows 7.
On my girlfreinds notebook (Asus EEE) with widows 7 it works well, same on my desktop with ubuntu. Even my router D-Link DI524UP it test cable say the "cable" is ok.
So I guess problem is SONY, either some specific settitng which SONY does on VAIO or hardware it self.