Step 1: Log into your SOPHOS UTM 9 appliance and go to "Definitions & Users"

 

Step 2: Click on "Network Definitions"

 

Step 3: Click "New Network Definition..." and create a "Host" for the computer you would like to Remote into by it's IP Address.

NOTE: Ensure that the "interface" is set to Internal

 

Step 4: Click on "Service Definitions" and add a "New Service Definition..."

 

Step 5: Here is where you specify the external Port for your connection

 

Step 6: Here is where you specify the internal Port of your connection (Port 3389 is the standard for Microsoft RDP)

NOTE: Your source Port needs to be the same as the Destination Port of Step 5

 

Step 7: Here is where you'll go to create the actual firewall rule. Go to "Network Protection" and click "NAT"

 

Step 8: Select "NAT"

 

Step 9: Click add "New NAT Rule..." at the top

Using service: This is the first service rule you created in "Step 5"

Change the destination to: This is the host you created in "Step 3"

And the service to: This is the second service rule you created in "Step 6"

Automatic firewall rule: This automatically creates a firewall rule to allow your RDP connection through