If you have AT&T’s internet service and you're using a UniFi router or firewall, you may want to set your AT&T modem to bridge mode. Bridge mode disables the modem's routing functions, allowing your UniFi device to handle all routing and firewall tasks. This setup also ensures your UniFi router receives a public IP address directly from AT&T, instead of a private one that’s typically assigned when the modem is in router mode.
Here’s a step-by-step guide on how to set your AT&T modem to bridge mode, ensuring that your UniFi device is directly handling your network traffic.
What You Need
AT&T modem (most likely a BGW210, Pace 5268, or similar model).
UniFi Router/Firewall (e.g., UniFi Dream Machine, UDR or UniFi Security Gateway).
Internet connection via AT&T.
Admin access to the AT&T modem’s settings and your UniFi router.
Why Set Your AT&T Modem to Bridge Mode?
Setting your modem to bridge mode is important for several reasons:
It allows the UniFi device to act as the primary router, handling all DHCP, NAT, and firewall functions.
It ensures you get a public IP address, which is ideal for certain setups, like hosting a server, using VPN services, or enhancing network security.
It simplifies your network management by consolidating routing responsibilities to one device.
Steps to Set AT&T Modem to Bridge Mode
Step 1: Log into Your AT&T Modem
Connect to your AT&T modem (either through Wi-Fi or directly using an Ethernet cable).
Open a web browser and go to the modem’s admin page by typing 192.168.1.254 into the address bar.
If behind the UniFi equipment you will need the modify the default LAN network from 192.168.1.1/24 to 192.168.14.1/24 for example before being able to open 192.168.1.254. Unless directly connected to AT&T modem.
Enter the admin credentials when prompted (usually located on the modem's label). By default, the username is often “admin,” and the password is printed on the modem itself.
Step 2: Access the Modem’s Settings
Once logged in, navigate to the "Home Network" tab (for BGW modems) or the relevant settings page depending on your modem model.
Look for the "LAN" or "Firewall" settings. This will vary depending on your model, but you are looking for options related to the network interface and routing functions.
Step 3: Enable Bridge Mode
In the modem settings, look for an option like “IP Passthrough”, "Bridge Mode", or "Pass-Through Mode". This feature will allow the public IP address from AT&T to be passed through to your UniFi router.
Enable “Bridge Mode” or “IP Passthrough”. When this mode is enabled, the AT&T modem stops performing NAT and routing functions. In the example below you will need to select "Allocation Mode" = Passthrough. Then you will need to select the MAC address from your UniFi Router.
Save the settings.
Reboot both modem and UniFi gear.
Step 4: Set Your UniFi Device to Handle Routing
Unplug the Ethernet cable that connects your computer to the AT&T modem.
Plug the Ethernet cable from the AT&T modem into the WAN port on your UniFi router or firewall (the UniFi device will now receive the public IP directly).
Turn on your UniFi router/firewall and wait for it to fully boot up.
Change the local LAN network to something other than 192.168.1.1/24. Example 192.168.14.1/24
Log into the UniFi Controller (via the web interface or mobile app) and ensure that the WAN interface is receiving a public IP address.
Go to Settings > Internet or Network settings, and confirm that the IP address shown is a public IP (often in the range of 70.x.x.x or 24.x.x.x for AT&T).
If it’s working, your UniFi device should now be in control of your network’s routing and firewall functions.
Step 5: Test Your Connection
Test your internet connection by browsing or running a speed test.
Check for any issues with IP address assignment, routing, or firewall features. If everything works correctly, your UniFi router/firewall is now managing your network’s traffic with a public IP from AT&T.
Troubleshooting
If you experience any issues, here are a few things to check:
Reboot your AT&T modem after setting it to bridge mode. Sometimes, changes require a restart.
Ensure your UniFi router is set to obtain an IP via DHCP on the WAN interface. This allows it to receive the public IP address.
Double-check IP Passthrough settings in the AT&T modem if your UniFi device isn’t getting the public IP.
If your modem doesn’t have a specific bridge mode, enabling IP Passthrough mode should work just as well for most use cases.
Conclusion
Setting your AT&T modem to bridge mode allows you to take full control of your home or office network with a UniFi router/firewall. By passing the public IP address directly to your UniFi device, you gain better network management, more advanced features, and improved security. Follow the steps above to configure your setup, and you’ll be ready to experience the power of UniFi routing with a direct public IP.
Have any questions or ran into any issues? Let us know in the comments!