Reactivate a Device

Duo Troubleshooting - Reactivating Devices

Duo Mobile is tied to a specific device's hardware security module (HSM), you will need to reactivate Duo Mobile on your device by logging into the Duo Portal.

For users who update their device (i.e. new phone), but have the same phone number, please follow the steps below to reactivate your device.

1. You will need to log into the SDSU Duo Portal screen to manage your Duo devices.

2. On your computer screen, you will be asked to provide your SDSUid login credentials and authenticate yourself.

3. After logging in, authenticate using your device. Choose an authentication either "Call Me" or "Enter a Passcode."

Note: If you typically receive a Push, the Push functionality will not work at this time since your device will need to be reactivated.

4. If you selected the "Call Me" option, you will receive a phone call. The phone call will instruct you to "Press any key on your phone to log in."

5. If you selected the "Enter a Passcode" option, a blue banner will appear on the bottom of the Duo Portal screen. Click “Text Me New Codes.”

A code will be sent to your mobile device via SMS text. Input the code in the blank box and click “Log In.”

6. You will receive a prompt that will ask you to "Stay signed in." Click "Yes."

7. After you authenticate your device, select the device you are reactivating from the dropdown menu on the Duo Portal screen. Then, select Device Options. Click Reactivate Duo Mobile.

8. Next, select the method of verification. For mobile devices, users can choose between a phone call or text.

Input the 6-digit code provided in the box and choose Verify and Continue.

9. On the Duo Portal screen, you will have to verify ownership of your device. Select either "Call Me" or "Text Me."

If you selected the "Call Me" option on the Duo Portal screen, you will receive a phone call. The phone call will instruct you to "Press any key on your phone to log in."

If you selected the "Enter a Passcode" option on the Duo Portal screen, a blue banner will appear on the bottom of the Duo Portal screen. Click “Text Me New Codes.” A code will be sent to your mobile device via SMS text. Input the code in the blank box and click “Verify.” Then, click "Continue."

10. On the Duo Portal screen, you will be asked to select the type of device you are reactivating.

11. On the Duo Portal screen,  you will see instructions to install Duo Mobile. Since these are instructions for a device reactivation, it is assumed that you already have the Duo Mobile app installed. Select I have Duo Mobile installed.

12. On the Duo Portal screen, a barcode and set of instructions will appear. Open the Duo Mobile app and follow the instructions to activate Duo Mobile.

If you have downloaded the Duo Mobile App, open the Duo Mobile app on your phone. Tap the “+” button. Scan the barcode on the Duo Portal screen with your device’s camera.

Once scanned by your device using the Duo Mobile app, you will be able to complete activatation for your device. Click "Continue."

13. If your phone does not have a camera or you are unable to scan the barcode, choose Email me an activation link instead.

14. On the device you are reactivating, check your SDSU email account for a message from Duo Security and open the link in the email.

If your phone asks which app to use to open the link, select Duo Mobile. Duo Mobile will be activated. Click Continue to finish adding your device.

15. Your device should now be reactivated! You will be brought back to the Device Management page on the Duo Portal screen.

16. For Duo MFA User Support, please visit the following links:

• IT Security Office Website
• Faculty and Staff - Submit a Ticket through SDSU ServiceNow or coordinate with you IT department.
• Students - Visit the Hub Help Desk.