> I would like to set up on it also the NAT as I've done on a mac68k, 
> but I suppose that the GENERIC kernel does not support this because 
> the sysctl "net.inet.ip.forwarding" is = 0.
> 
> Where I can download another kernel to do this job, or can someone 
> compile it for me?

You don't need a new kernel. Just run:

	sysctl -w net.inet.ip.forwarding=1

> Another question:
> On this machine I have only one ethernet interface, so I've used 
> ifaliases to manage another network, can the NAT be done?

I think so.

-- Dan