I want to use my linux box as a router/firewall. Do I need two network cards, or can I assign multiple IP addresses to one nic? If I can get away with only one nic, will I have problems with collisions? I would think not... since the cable modem is a 10mbit connection but the linux box and win2k machine both have 100mbit nics.. using a 5 port netgear switch.

You need two nic's. You cannot assign two ip addresses to one nic. It is impossible. Give your linux box a real ip and a private like 192.x.x.x Then go to http://www.e-infomax.com/ipmasq/ Follow the instructions, ipmasq will give you a firewall as well nat. Follow the instructions for ipmasq, they give you example config files, that you can use. All you have to do is modify them slightly with your nic ip info. works great...I use a linux box and ipmasq to firewall off 48 pc's running linux. One real world ip and a inside ip of 192.168.0.x. hope this helps jerry

Well, actually you can assign several ip addresses to a single nic. The same way you assign eth0 an ip address, you can assign to eth0:0, eth0:1, eth0:2, etc. Therefore, technically, but not ideally, you can set up a router with one nic. Charles

I use one nic with command ifconfig eth0:0 with my ipmasq.

great. I figured if NT can do multiple IP's on a single nic then linux should also. Question 2 - in NT if I set my nic for DHCP then I can't assign static IP's. does this hold for linux too? or can I set eth0:0 to dhcp (cable modem requires it) and eth0:1 to a static ip??? Question 3 - how much additional latency can I expect? Or is it so fast that my pings won't change???

http://www.freesco.info/