I have a problem with a Fortinet Fortigate appliance.
In the local network there is a Windows 2000 Server machine runing DNS server and IIS with a local IP 192.168.10.7 ( hosting a website) this machine is at a DMZ behind a Fortigate 200 Firewall, and is reachable from the internet using "Static Nat" from a public IP to the internal IP of this Windows Server.
I recently install a new Linux machine on the same LAN with IP192.168.10.10 running Apache on default port 80 running a website and want this website can be viewed from the internet, so i tought that port redirection was the solution and setup a "Port Forwarding" rule on the Fortigate opening a 8088 port on external that redirects to the internal ip ( 192.168.10.10 ) on port 80 ( http ).
Unfortunately we have just only one public IP , and the port redirection did not work, may be because the "Static Nat" that makes work the website on the windows box supersedes the Port Forwarding rule. So I disable the Static Nat to the Windows box and create Port Forwarding from external to ports 80tcp, 53tcp, 53udp. My linux site on port 8088 works, the windows site works ... but after a time the Domain Name that the Windows serves goes down from Internet. When I enable NAT again to the Win box, the DNS works again!.
What i´m doing wrong?.