After the extender Linksys RE6400 setup, it is quite necessary to change its password to make it safe. As the older default password is really easy to guess which is why the network can have some unauthorized users on it. So, to change the password, first, make sure to straighten out your web browser, therefore enter the router's default IP address into the address bar then press the Enter key. Once you do that a Linksys Extender login page will appear to you on the screen. That is the setting so just open it. Just open the page and thereafter, choose the password setting and then select the encryption option. Finally, apply your new password.