I use a cross over utp cable with my PC and Amiga 4000. The PC has two network cards to make this work. One for internet connection and one for the Amiga.
This my setup:
PC:
IP: 192.168.0.1
Sub: 255.255.255.0
Amiga:
IP: 192.168.0.2
Sub: 255.255.255.0
Gateway: 192.168.0.1
And then I shared the internet connection on the PC.
Works for me!