Opening a new port in Redhat 8.0

[RiezalR]

My network has a Redhat 8.0 as its gateway and several other windows machines connects to this gateway to access the internet. The RH 8.0 is the server/firewall for my home network. All of them are connected via a swtich. Now this is what i want to do:

I want my RH 8.0 to allow remote access to port X and at the same time forward any requests to port X to my Windows XP machine. I've tried playing around with the firewall, to allow routing port X to my WindowsXP machine. But the question is, how do I actually go about opening this port X on linux? How do i make Linux listen on port X? My firewall has been set to forward any requests to port X to my Windows XP machine, but for this to work i need to make linux listen on port X. How do i do this?

I tried using SSH and Netcat, but those didnt help. When i use SSH and do a local scan (127.0.0.1) the port X is opened. But when i scan my remote IP, the port X is not opened. Any ideas?

 

[flugh]

I'm not the most experienced at actually doing this, so here's a link to a good HOW-TO with some examples:

http://www.tldp.org/HOWTO/IP-Masquerade-HOWTO/firewall-examples.html

The way to do it depends on your kernel version, ipchains or iptables, etc. --
JR

 

[RiezalR]

Well thanks for the link, but that is what my firewall is all about. I am already using that firewall configuration, plus i added a rule to allow incoming packets to port X. However, when i do a remote scan on my box, that port does not seem to be open. I need to know how to make remote port X open for incoming traffic. Maybe my firewall rule syntax is wrong, i can't tell. Anyone know the proper syntax for IPTABLES rules to allow incoming traffic to a specific port?

 

[machinetype]

When you do an ipchains -L where does the rule show up in the chain? If you have a deny rule set up above the allow rule you set up for port X it will deny first. To set a rule in a specific order in the chain it should look like:

ipchains -A input 1 -p tcp -i eth0 -s 0.0.0.0/0 -d 192.168.1.0/24 25 -j ACCEPT

In this example I said to append this rule as rule #1 in the input chain. I specified tcp as the protocol with the -p switch (you must specify protocol if you want to use a port #)

If this is not the problem it would be helpful to know what port(application) you are trying to let through and what program you are trying to scan with.