Duo (Two-Factor) Authentication

What is Duo?

Duo is a two-factor authentication (2FA) service that Dartmouth has rolled out to replace Security Questions on Dartmouth logins. Two-factor authentication with Duo is more secure, and easier than security questions.

We used to use security questions to provide an extra layer of protection — in addition to your password — between you and potential hackers. But security questions can be stolen too. Duo uses your cell phone or another registered device as a different kind of extra barrier between you and hackers.
After you enter your password, Duo will request additional verification from something that only you have access to: your smartphone, landline, or a Duo security token. If you don’t want to use your phone, we can help set up another authentication device — just contact us and ask!


To register a device, go to:


For more details see Dartmouth ITC's documentation: Two-Factor Authentication (2FA) with Duo

Common issues

Re-activating Duo mobile app when you replace your phone or SIM card

These instructions apply if:

  • You have previously registered a cell phone in Dartmouth's Duo program
  • Your phone or SIM card has been replaced but you kept the same phone number
  1. Go to 2faenroll.dartmouth.edu
  2. After entering your netID and password do NOT do the Duo authentication you will be prompted for; instead click on My Settings & Devices in the left sidebar 
  3. You will be prompted to Duo again -- this time you should actually do it. You'll need to use a different device or accept a phone call or passcode texts to your phone.

  4. Find your phone in your device list; click Device Options
  5. Choose Reactivate Duo Mobile

  6. Follow the on-screen instructions from here

Managing shared accounts

If multiple people need to access to a shared Dartmouth account -- for example, a student club account -- each accessors Duo device should be added to the account. See Duo's instructions for adding new devices to an account: https://guide.duo.com/add-device

Keep in mind: 

  • Do not accept Duo requests that you did not generate! 
  • Delete devices that should no longer have access to the account!