Troubleshooting Common Port Forwarding Issues

Port forwarding can be a powerful tool for accessing devices and services on your network from outside your home or business. However, it can also be frustrating when things don’t work as expected. In this final blog post of our Port Forwarding series, we’ll look at some common port forwarding issues and how to troubleshoot them.

Check Your Router Settings:

The first step in troubleshooting port forwarding issues is to check your router settings. Make sure that the port you’re trying to forward is not already in use by another device or service. You should also check that the correct protocol (TCP or UDP) is being used and that the forwarding rule is correctly configured.

Verify The Internal IP Address of the Device You are Connecting To

Another common issue with port forwarding is incorrect mapping of the port to the internal IP address of the device you are connecting to on your network. To find out more on how to check the internal IP address, check out our knowledge base article: How to Port Forward – General Guide to Multiple Router Brands

Check Your Firewall:

A firewall can block incoming traffic to your network, including traffic that you’re trying to forward. Make sure that the firewall is not blocking the port you’re trying to forward. You can check your firewall settings to see if the port is open or closed.

Including the Port Number at the End of Your Hostname:

If you’re using port forwarding to access a device on your network remotely, you’ll need to include the port number at the end of your hostname in order to connect to the correct device. For example, if your hostname is “” and you’re trying to access a web server running on port 80, you would need to use the hostname “” to connect to the correct device.

Note: default ports 80 and 443 do not need to be added to the end of the hostname.

It’s important to note that not all protocols use the same default port numbers. For example, HTTP uses port 80 by default, while HTTPS uses port 443. Make sure to check the documentation for the protocol or application you’re using to determine the correct port number to use.

A list of common ports can be found here: TCP and UDP port numbers | Most Common Port Numbers

Test Your Forwarding:

After checking your router settings, verifying your public IP address, and checking your firewall, it’s time to test your forwarding. You can use an online port forwarding tester or a tool like to test whether the port is accessible from outside your network. If the port is still not accessible, double-check your router settings and try again.

It is important to note that in some cases, your internet service provider (ISP) may not allow you to forward ports on your own. This is often the case for ISPs that use carrier-grade NAT (Network Address Translation) to conserve public IP addresses.

In such cases, you may need to contact your ISP to request that they forward a port for you. This can typically be done by contacting their customer support team and providing them with the details of the port you need forwarded and the device on your network that requires access.

By following these best practices and troubleshooting tips, you can make sure that your port forwarding is set up correctly and accessible from outside your network. Remember to always keep your router settings and firewall up to date for maximum security.

For more information about port forwarding, visit our extensive Knowledge Base or reach out to our Customer Support team. We are dedicated to helping you make the most of your No-IP service and ensuring that your remote access needs are met with ease and security.