Step 1: Login to your ASUS router via the default gateway.
Step 2: Click on “WAN” under “Advanced Settings.”
Step 3: Click on the “DDNS” tab.
Please Note: Depending on your firmware this page may differ.
Step 4: Click on “Yes” next to Enable the DDNS Client.
Step 5: Select No-IP on the Server dropdown. Then enter your No-IP hostname, username and password.
Step 5: Click “Apply.”
Congratulations, the ASUS router should now send No-IP updates whenever the IP address changes.