Problem: This article outlines the detailed steps for how to configure FortiGate port forwarding for RDP.
The Process is:
- Setup a Virtual IP (with port forward enabled)
- Create a Virtual IP Group
- Allow traffic to the Virtual IP Group
Content Summary
FortiGate Port Forwarding: Create a Virtual IP
FortiGate Port Forwarding: Create a Virtual IP Group
FortiGate Port Forwarding: Fortigate Add an ‘Address’
FortiGate Port Forwarding: Allow Port Forwarded Traffic
FortiGate Port Forwarding: Troubleshooting Port Forwarding
FortiGate Port Forwarding: Create a Virtual IP
Step 1: Go to Policy and Objects >Virtual IPs > Create New > Virtual IP.
Step 2: Give it a name and configure the settings as below:
- Set the Interface to the outside/WAN interface.
- External IP set to the public IP address of the firewall.
- Mapped IP address set to the internal IP address of the server you are forwarding to.
- Enable Port Forwarding.
- Select TCP or UDP.
- Type in the port(s) you want to forward.
Settings to create new Virtual IP
Step 3: Click on the OK button.
FortiGate Port Forwarding: Create a Virtual IP Group
Step 1: From the Virtual IP menu > Create New > Virtual IP Group.
Step 2: Give the group a name and configure the settings as below:
- Set the Interface to the outside/WAN interface.
- Add in the Virtual IP you created above.
Settings to create a Virtual IP Group
Step 3: Click on the OK button.
FortiGate Port Forwarding: Fortigate Add an ‘Address’
If you are port forwarding something like HTTP/HTTPS to a web server, or SMTP to a mail server you can skip this step. For most port forwarding scenarios you would set the source to ALL. Anyway for completeness here’s how to create an Address object.
Step 1: Go to Policy & Objects > Addresses > Create New > Address.
Step 2: Give it a name and configure the settings as below::
- Set the Type to Subnet.
- Type the IP into the IP Range box.
- Set the Interface to outside/WAN.
Settings to add an Address.
Step 3: Click on the OK button.
FortiGate Port Forwarding: Allow Port Forwarded Traffic
Step 1: Go to Policy and Objects > IPv4 Policy or Firewall Policy > Create New.
Step 2: Give it a name and configure the settings as below:
- Incoming Interface: Outside / WAN
- Source: For RDP specify the single address you created above for all other port forwarding simply use ALL instead.
- Destination: Your Virtual IP Group
- Schedule: Always
- Service: RDP (or the port you are forwarding if different)
- Allow: Accept
Settings to Allow Port Forwarded Traffic
Step 3: Click on the OK button.
FortiGate Port Forwarding: Troubleshooting Port Forwarding
You can see what’s going on by using the packet sniffer in the firewall.
diagnose sniffer packet {interface} 'host {External IP} and port {Port Number}' 4
e.g: diagnose sniffer packet wan 'host 234.234.234.234 and port 3389' 4
Troubleshooting FortiGate Port Forwarding
Alex Lim
Alex Lim is a certified IT Technical Support Architect with over 15 years of experience in designing, implementing, and troubleshooting complex IT systems and networks. He has worked for leading IT companies, such as Microsoft, IBM, and Cisco, providing technical support and solutions to clients across various industries and sectors. Alex has a bachelor’s degree in computer science from the National University of Singapore and a master’s degree in information security from the Massachusetts Institute of Technology. He is also the author of several best-selling books on IT technical support, such as The IT Technical Support Handbook and Troubleshooting IT Systems and Networks. Alex lives in Bandar, Johore, Malaysia with his wife and two chilrdren. You can reach him at [email protected] or follow him on Website | Twitter | Facebook
