[X4U] Mac mini as an Internet Gateway.

[Robert Tillyard]

I'm planning on using Mac OS X Server 10.4 on a Mac mini to handle e- 
mail/web proxy for a group of computers (Mac and Windows). Our ISP  
gives us a router with a fixed public IP Address.

I'm currently using a UNIX box with two network cards to do this, one  
card has the public IP address and the other is our internal network.

Is it feasible to so this on a Mac mini with a single ethernet port?  
I'm wondering if I can use ifconfig to 'alias' the external IP  
address to the same ethernet port that has our internal address. I  
know it would be better to have two network cards but I don't have a  
G5 or XServe spare to do this with.

Thanks, regards, Rob.