From UntangleWiki

My port forward isn't working. Why?

Follow the Port Forward Troubleshooting Guide to see if you can discover the issue.

I setup a port forward for HTTPS (port 443) and it is not working. Why?

Untangle and many of the applications use port 443. In order to forward port 443 you need to move Untangle off of port 443 to a different port. This can be done in config->administration under "External Administration." Also confirm that your web filter doesn't have "Categorize HTTPS traffic by IP address" enabled. This will cause connection refusal/time out errors.

I setup a port forward to my FTP server and it is working but transfers fail. Why?

FTP has multiple connections. If you setup a port forward for the control session (port 21) then you must also setup a port forward for the transfer sessions. You can do this in multiple ways.

1. Configure your server to use a range of ports for a transfer (10000-20000) and configure Untangle to forward all of these ports to the FTP server.
2. Use 1:1 NAT

Does Untangle support 1:1 (One to One) NAT?

Yes, Read more about how to setup 1:1 NAT.

What is "Destined Local?"

Destined Local is a flag for port forward rules. It matches on traffic destined to the local untangle machine and one of its IPs. This flag is usually used when you want to redirect a port on the Untangle Server (and all of its IPs) to another server.