Duo Expansion to Microsoft 365 Services

On June 1 2021, Duo Two-Factor Authentication will be expanded to include Microsoft 365 applications and email (this includes university email accounts, OneDrive, Teams, Stream and more).

help.mail.colostate.edu is the primary campus resource to find information regarding Microsoft 365 services. As Duo expands to protect these services, we’ve provided links to resources for setting up email on mobile devices as well as what to expect when accessing email and other Microsoft applications with Duo.

Frequently Asked Questions:

What can I use as a second factor device?

You can register and authenticate using any and all of the following methods:

•    The Duo Mobile App (Recommended): Download the Duo Mobile App from your smartphone or tablet’s app store. This method will allow Duo to push a message to your phone or tablet where you can verify your identity by tapping on the screen.

•    Any Phone Number: You can register your cell phone, desk phone, home phone, etc. and the system will call you to validate your identity.

•    A Hardware Token: These can be purchased from RamTech and will be registered to your account at time of purchase. Hardware tokens generate a six-digit code that you can use to authenticate.

We recommend that you setup more than one device as a 2nd factor authentication method with Duo. If you lose, misplace or simply forget a device, having a second registered device will save the day.

Can I set up more than one device?

Yes, we recommend that you set up more than one device as a 2nd factor authentication method with Duo. If you lose, misplace or simply forget a device, having an additional registered device (like your desk phone or a hardware token) will save the day.

If you do not have an alternate/back-up device registered, you will need to contact the CSU Central IT Support Helpdesk at (970) 491-7276 or help@colostate.edu for assistance with setting up a new device.

What do I do if I'm locked out or don't have a back-up device registered?

If you’ve lost or are unable to use your cell phone, hardware token, or any other device you’ve registered with Duo and do not have an alternate/back-up device registered, you will need to contact the CSU Central IT Support Helpdesk at (970) 491-7276 or help@colostate.edu for assistance with setting up a new device.

I lost a device registered with Duo – how can I remove this device as my 2nd factor?

If you’ve lost your cell phone, hardware token, or any other device you’ve registered with Duo, you can remove it through the Duo self-service application located on the eID website if you have another device registered.  If you do not have a backup device registered with Duo, you will need to contact the CSU IT Central Support Helpdesk for assistance at (970) 491-7276 or help@colostate.edu.

I got a new phone – do I need to register it?

Yes! Whether your phone number has changed or you have a new device (with the same number), you’ll need to go through the registration process again.

  • If you have an alternate/backup device registered:
    • Log in to the eID Duo Self Service page with your eName and ePassword.
    • Find your old device (or number) under the Registered Devices table and click the ‘delete’ link to remove it.
    • Click on the ‘+Register Device’ link to register your new device (or number).
  • If you do not have an alternate/back-up device registered in Duo, contact the CSU Central IT Support Helpdesk for assistance at (970) 491-7276 or help@colostate.edu.

I registered more than one device – how do I select which device to use when prompted by Duo?

Upon logging in with your CSU credentials, the Duo prompt will populate allowing users to choose how to verify their identity.

If you have more than one device registered, make sure to select the one you want to use for this session from the Device dropdown menu.

You can then select which authentication method you want to use with that device. For more information on the authentication process, see the What to Expect: Duo Authentication guide.

Note: The default device listed in the Duo Prompt will be the one listed at the top of your list of Registered Devices on the eID Duo Self Service page.

Duo Self Service Registered Devices Summay Screenshot

Where do I get a hardware token?

You can buy a hardware token at RamTech for $23.75 and the staff will register the token for you.  For information on using a hardware token to authenticate, see the What to Expect: Duo Authentication guide, “Enter a Passcode – Using a Hardware Token” section.

Can I register an international phone number?

International phone numbers are supported in DUO. When filling out the device information, enter a plus sign (+), followed by the Country Code, and the phone number, in the Phone Number field. These numbers should be all in one string; no spaces or dashes. For example: +441234567890

How do I resolve Duo Prompt display issues related to iOS or macOS content restrictions?

If the Duo Prompt does not display as expected while attempting to log in on iOS or macOS, please see this Duo support article for resolution.

I don't have cellular connectivity. How do I use Duo?

For any situation where you are outside of cellular reception — whether for a short time in an area of low signal around town, because your phone is in airplane mode while traveling, or because you’re abroad in a country with more limited networking infrastructure or restrictive internet policies — Duo supports multiple methods for completing two-factor authentication.

  • If you’re traveling with an international data plan on your smart phone, the Push feature in the Duo Mobile App should work as normal.
  • The Duo hardware token, available for purchase at RamTech, is a device that does not rely on network communication. A push of the button provides a one-time code that can be typed into the Duo prompt.
  • The Duo Mobile App, on a cell phone or tablet, also has a one-time code feature that functions even when the device can’t reach the network.
    • Generate a passcode in the Duo Mobile app by tapping the down arrow next to “Colorado State University”. The app will populate a 6-digit code under the Colorado State University account that can be typed into the Duo prompt.

What is Duo Restore and what should I do if it pops up?

Duo Restore is not currently supported at CSU.  Our recommendation is to answer ‘No’ to enabling it.

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