Configuring port forwarding

FortiMail port forwarding allows remote computers, for example, computers on the Internet, to connect to a specific computer or service within a private local area network (LAN). Port Forwarding is useful when FortiMail is deployed as a gateway and you want external users to access an internal server via FortiMail.

For example, FortiMail port1 is connected to the Internet and its IP address 192.168.37.4, port 7000, is mapped to 10.10.10.42, port 8000, on a private network. Attempts to communicate with 192.168.37.4, port 7000, from the Internet are translated and sent to 10.10.10.42, port 8000, by the FortiMail unit. The computers on the Internet are unaware of this translation and see a single computer at 192.168.37.4, port 7000, rather than the 10.10.10.42 network behind the FortiMail unit.

To view and configure port forwarding rules

1. Go to System > Network > Port Forwarding.

Figure 113:Port Forwarding tab

Destination Port Displays the assigned port number of the destination computer.

2. Select New to configure a new forwarding rule or double-click a rule to modify it.

A dialog appears.

Figure 114: Port Forwarding dialog

3. In Protocol, specify the protocol that the rule will apply to: TCP, UDP, or Both.
4. In Host IP and Port, enter the IP address and port number that will be mapped. In most cases, they are the IP address and port of the receiving FortiMail interface. In the above example, they are 192.168.37.4 and 7000.
5. In Destination IP and Port, enter the IP address and port number that will be mapped to. In most cases, they are the IP address and port of the system behind the FortiMail unit. In the above example, they are 10.10.10.42 and 8000.
6. Click Create.