iptables forwarding question

kloppster · 06-15-2005, 12:00 PM

I have setup most of my iptable rules without a problem and they all seem to work fine, except one. The one I am having a problem with is forwarding local traffic heading for our external ip address back to an internal server (port 80). Whatever I do the connection just dies on me. However When connecting from an external location everything works fine and my request is forward to the internal web server. Any ideas?

comprookie2000 · 06-15-2005, 05:41 PM

Do you mean computers on the lan being able to access the web server?

jtshaw · 06-15-2005, 09:00 PM

Moved: This thread is more suitable in Linux - Security and has been moved accordingly to help your thread/question get the exposure it deserves.

Capt_Caveman · 06-16-2005, 01:04 AM

This is likely due to the "local DNAT problem" where the reply from the webserver is coming from the local IP rather than the external IP that the client is expecting. Take a look at the following links that explain it in more detail and ways to solve it using iptables. You can also fix it using local DNS.

http://iptables-tutorial.frozentux.n...tml#DNATTARGET
http://www.netfilter.org/documentati...-HOWTO-10.html