You want to have a secure Password for the router to restrict access to the router settings.
Access the router configuration pages by opening a Web browser and typing 192.168.1.1 and pressing ENTER.
Enter your login and password when prompted, then press OK.
Click Login on the Security menu.
To change your user name and/or password, enter the new user name and password and click Save at the bottom of the page. You will need to log in to your router with the new user name and password.
Password Rules:
The Wireless ASDL2+ Router lets you set a password up to 15 characters long. The most secure passwords are usually between 8 and 15 characters long.
The router will allow you to enter a space or other punctuation in your password.
Use a mixture of upper (A through Z) and lower (a through z) case letters.
Adding numbers 0 through 9 to a password increases security.
Use ASCII symbols, such as ~ ! @ # $ % & ^ *, etc, to further increase the security of your password.