To put your gateway in IP Passthrough mode, first connect your laptop or computer to the gateway. Then, connect Velop to your gateway.
Open a web browser and enter the IP address of your gateway located at the back label (ex. 192.168.1.254). Log in to the web-based setup page using the Access Code which you can find on the label of your gateway.
Select Firewall and click IP Passthrough.
On the Allocation Mode section, select Passthrough from the drop-down menu.
Select DHCPS-fixed from the drop-down menu in Passthrough Mode. Then, on the Manual Entry section, enter the MAC address of the Velop system's primary node which you hardwire with AT&T's gateway. Click the Save button to complete the setup.
NOTE: You can find the MAC address from the bottom label of the Velop node.
You're almost done!
Once you're done setting up the gateway, you may now proceed in installing your Velop system.