IT Knowledge BaseGeneral TopicsSecurity Faculty/Staff/Emeriti: Two-Factor Authentication (2FA)Enroll in Duo Security: Adding a Mobile Device to Your Duo Account

Enroll in Duo Security: Adding a Mobile Device to Your Duo Account

Duo is the two-factor authentication (2FA) service CSUF is using to secure login attempts to various campus services and applications. This article describes the steps needed to add a mobile device to your Duo account; this will allow you to use the mobile device to authenticate with Duo.

1. Install the Duo Mobile app on your mobile phone from either Apple Store or Google Play Store.

Within each app store, search for Duo Mobile and install it. In this screenshot below it only gives the option to Open because it's already installed on this device.

Duo Mobile app in the apple app store

2. Open your web browser to the CSUF Duo Two-Factor Authentication Setup website.

3. Enter your campus username and password. Place a checkmark next to I'm not a robot. Then click Login.

sign in prompt in duoauth.fullerton.edu
  1. Enter your campus username and password. This is the same login/password that you use for the campus portal.
  2. Place a checkmark next to I'm not a robot.
  3. Then click Login.

4. Click on Add a new device in the left menu.

You do not need to choose an authentication method on this screen, however you will need to do it on the next screen.

Add a new device prompt

5. Double check the authentication device that is selected. Then click Call Me to authenticate by phone. Or click Enter a Passcode to verify by text message.

For many users, the default authentication device is your office desk phone. For other users, it is a mobile phone number that you provided to your Department IT Coordinator (DITC).

add new device prmpting you to authenticate first
  1. Note the authentication device that is selected; the last four digits should tell you which device it is. Make sure you have that device with you.
  2. Click Call Me and you will receive a phone call from Duo with instructions on how to authenticate (normally  just press a number on your phone's dial pad).
  3. Click Enter a Passcode to get a text with a verification code.

6. Select Mobile phone and click Continue.

mobile phone

7. Enter your mobile phone number. Place a checkmark to confirm the phone number Then click Continue.

enter your phone number
  1. Enter the 10 digit phone number for your cell phone.
  2. Place a checkmark to indicate the phone number is correct.
  3. Then click Continue.

8. You may be prompted to choose the operating system (OS) of the device you are adding. Select it and then click Continue.

phone type

9. Click I have Duo Mobile Installed. If you intend to use the Duo Mobile app, please make sure you download it from the Apple App Store or Google Play Store first.

For tablets, you will have to use the Duo Mobile app. For mobile phones,  you do not need to use the Duo Mobile app, but you will need to click  this button to finish adding your new phone.

Install Duo Mobile for iOS

10. Open the Duo Mobile app on your device. Tap either Add Account or the plus sign icon at the top.

When opening up the Duo app for the first time it will ask you for permission to send you notifications; tap Allow.

Welcome to Duo Mobile

11. Tap OK to allow Duo Mobile to access the camera if prompted.

allow camera

12. Hold your device up to the laptop/computer screen to scan the QR code.

hold up to screen

13. Duo is now connected to your mobile device.

 Notice that another way you can use your mobile device with Duo is to generate a passcode.

Duo passcode

14. On your computer/laptop, click Continue to save your changes. You're done!

activation complete

15. Notice on the My Settings & Devices page, you can choose your default device. You can also choose what happens when you log in. If you make any changes to these fields, be sure to click Save.

Want to automatically get a push notification to your default device? Under When I log in, choose Automatically send this device a Duo Push.

Default device and when I log in
  1. Default Device allows you to specify which of your devices appears by default on any Duo login page. You'll still be able to use the drop-down menu to select another device, but this saves you some time if there is a particular device you will frequently use.
  2. When I log in allows you to have Duo automatically send you a push notification to a device with the Duo Mobile app installed. Note that Duo will send the push notification to your default device.

Need More Help?

Contact the IT Help Desk at helpdesk@fullerton.edu or 657-278-7777