Once you perform the Asus router login on your Asus Ac1900 via http://router.asus.com or 192.168.1.1 IP address, follow given steps.
• Open the Asus Ac1900 Router, setup page & click on the Administration section.
• Next, click on the reset option.
• This will start the reset process and finishes up automatically. • Once your Asus router Ac1900 done with the reset, re-configure it, by using the default Asus router login credentials.