You must know the few details of your router before modifying it’s settings. Your router IP address, username and login credentials, which are there in the manual. Let’s have a look on how to access AT&T router. Open a web browser and type 192.168.1.254 in the URL bar. Now, enter the login credentials. If you haven’t change the settings before you can login through default credentials. You will be directed to login page thereafter and modify the settings.