Routing with Linux

[Burner <burner@clanpips.dk>]

Hi

My boos just asked me to build a Linux firewall to protect our servers, we 
have about 20 servers, all configured with only the public (internet) IP, and 
connected through a switch directly to our IPS's router.
I've only build firewalls for small lan networks using NAT with 
iptables/ipchains.

I've read some iptables and iproute2 howtos, but i realy do not know where to 
begin, i dont even know if the hardware will be sufficient. P3/800 128Mb ram 
and two good NIC's.

We don't need any advanced routing like bandwith balancing etc. I just need 
to block most ports from public access and allow the servers (win) to update 
from the internet.

I would like to keep the public IP addresses on the servers if possible.

Maybe i should configure the linux router with all the external IP's on one 
NIC, and give the protected servers local IP addresses. then NAT the public 
IP/ports to the servers using iptables, this is a way to do it, but is it i 
good way?

I would be happy to recive any hints from someone who has done anything like 
this before.

//Burner