I'm running CentOS 6.4 as a virtual machine on Hyper-V. I'm setting it up as a web server. I've had it working before in a different location. I can't seem to get the ports to forward now. The router is set up correctly for forwarding to the virtual machine (on it's own IP, separate from the host machine). I used nmap to see what ports are open on on CentOS through IPTables, and everything seems to be open (20,21 for FTP and 80 for HTTP). I check on canyouseeme.org and none of the ports are open, the connection times out. Any ideas?
Even though the ports are configured to forward on the router, is there any firewall functionality turned on? You may need to still allow those ports first, as the firewall may block the traffic before it even hits the port forwarding function.
Also have you tried configuring the web server as the DMZ host on the router to see if that works?