Configure iptables to forward ports to an internal server

ikaro_tatsomura · 02-08-2007, 06:08 PM

Hi

I have a Compaq ProLiant server (running Debian 3.1 r2). It's a HTTP and DNS server. The server have 2 NICs:

eth0: 192.168.x.1
eth1: External (and static) IP from my ISP.

Well, I've more servers:
* A FTP server (192.168.x.2)
* A SSH server (192.168.x.3)
* A database server (192.168.x.4)
* A SMTP/POP3 server (192.168.x.5)

At this moment, I need to set the FTP server to public access (like HTTP server) using the same external IP from my ISP.

All server are in different PCs. My question is:

How I can redirect the incoming traffic (FTP request) from Internet to my internal FTP server using Iptables?

I'm using Linux kernel 2.6

Thanks in advance

Miguel

Brian1 · 02-08-2007, 06:45 PM

You will want to use the DNAT option. Example is forward ssh port 22 from eth0 to 192.168.69.69 port 22.

/sbin/iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 22 -j DNAT --to-destination 192.168.69.69:22

Brian