A:Answer Yes, you can use Nest Wifi system with your AT&T router. But we recommend wiring Nest Wifi router directly to your modem's WAN port to set it up as your primary router. If you would like to keep your current router between your modem and Nest Wifi router, we recommend putting your AT&T router in Bridge mode to avoid a Double NAT which can cause connectivity issues with online gaming, port-forwarding, and connected devices. You can learn more about Bridge Mode here: https://support.google.com/googlenest/answer/6240987