Opening Ports in a Cisco DPC3941T Router

Thumbnail image of Port Forward Staff
Port Forward Staff
September 02, 2017 (Last Updated: ) | Reading Time: 3 minutes

Cisco DPC3941T - XFINITY routers include a very basic firewall that helps protect your home network form unwanted access from the internet. Since this firewall blocks incoming connections you may need open a port through it for certain games and applications. This process of opening a port is frequently called a port forward, since you are forwarding a port from the internet to your home network.

The basic process to open a port is:

  1. Setup a static IP address on either your computer or device that you want to forward a port to.
  2. Login to your Cisco DPC3941T router.
  3. Navigate to the port forwarding section.
    • Click the Advanced link.
    • Click on Port Forwarding.
    • Click the Add Service button.
  4. Create a port forward entry.

While these steps might seem difficult at first, we will walk you through each step for your Cisco DPC3941T - XFINITY router.

We think that forwarding a port should be easy. That's why we created Network Utilities. Our software does everything that you need to forward a port.

Get Started Now!

When you use Network Utilities you get your port forwarded right now!

Step 1

It is important to setup a static ip address in the device that you are forwarding a port to. This ensures that your ports will remain open even after your device reboots.

This step is important because you want a permanent IP address in your device. If you do not set up a permanent IP address in your device, then when you device reboots it may get a new IP address.

Use a VPN Instead

Have you considered using a VPN instead of forwarding a port? For most users, a VPN is a much simpler and more secure choice than forwarding a port.

NordVPN faster than ever deal!

We use and recommend NordVPN because not only is it the fastest VPN, it includes a new feature called Meshnet that makes forwarding a port no longer necessary for most applications. With NordVPN Meshnet, you can connect to your devices from anywhere in the world, completely secure, over a highly encrypted VPN tunnel.

Every time you click on one of our affiliate links, such as NordVPN, we get a little kickback for introducing you to the service. Think of us as your VPN wingman.

Step 2

Now we are going to login to your Cisco DPC3941T - XFINITY router. Your router has a web interface, so you will login to it using your web browser. This can be either Chrome, Firefox, Internet Explorer, or Edge. It usually does not matter which browser you choose to use.

Open up your web browser and find the address bar. It should look something like this:

Image of a browser address bar
Browser address bar

Above is an example of what a web browser address bar looks like. Find the address bar in your router and type in your router's IP address.

The default Cisco DPC3941T IP Address is: 10.0.0.1

After entering the IP address of your router you can simply press enter. If all goes well you will see the following screen:

Cisco DPC3941T - XFINITY Login
Cisco DPC3941T - XFINITY Login.

You should see a box prompting you for your username and password.

Enter your username and password, and then click the Login button to log in to your Cisco DPC3941T - XFINITY router.

Cisco Usernames and Passwords

If your username and password do not work then please visit our Default Cisco Router Passwords page.

If you still can't login to your router because you forgot your Cisco DPC3941T - XFINITY router username and password, use our How to Reset a Router Password guide to set your Cisco DPC3941T - XFINITY router back to its factory settings.

Step 3

Now we need to find the port forwarding section in your router. Here's how you do it. Starting from the first page in your router:

Cisco DPC3941T - XFINITY Gateway At a Glance
Cisco DPC3941T - XFINITY Gateway At a Glance.

Click the Advanced link near the left of the page.

You should now see a new menu. In this new menu, click Port Forwarding.

Cisco DPC3941T - XFINITY Port Forwarding
Cisco DPC3941T - XFINITY Port Forwarding.

Click the Add Service button near the center of the page.

Cisco DPC3941T - XFINITY Port Forwarding Add
Cisco DPC3941T - XFINITY Port Forwarding Add.

Step 4

Here are the ports to forward for Xbox Live:

  • TCP Ports: 3074
  • UDP Ports: 3074

If you are looking for the ports for a different application you can find it by either:

Don't forget to sign up for NordVPN's promo deal before it's gone.

NordVPN faster than ever deal!

You might notice that most of our site doesn't have ads on it. This is because we use partnerships with companies like NordVPN to keep the site running. Thank you for supporting us by using our referral links.

Select Other from the Common Service dropdown box.

Put a name for this forward in the Service Name box so that you can remember why you set this forward up. The name does not matter so pick something that has meaning to you.

Use the Service Type dropdown box to select the protocol type of the ports you are forwarding.

Enter the IP address that you are forwarding ports to in the Server IP Address box. This is either the IP address of a computer or the IP address of another device on your network.

If you are forwarding a single port, enter that port number into the Start Port and the End Port boxes. If you are forwarding a range of ports, enter the lowest number of that range into the Start Port box. Then enter the highest number of that range into the End Port box.

When you are done click the Save button.

Your ports should now be open. It is time to test them.

Test if Your Ports are Open

Now that you have forwarded ports on the Cisco DPC3941T - XFINITY you should test to see if your ports are forwarded correctly.

To test if your port has been properly forwarded, you can use our Network Utilities tool, which includes a free Open Port Checker. Our Open Port Check tool is the only online port checking tool with Guaranteed Results.

More From Portforward