Update 11/7/2019 3:46 PM:
Duo has made a change to the default number from which phone call authentications are sent.
The new caller ID from Duo is +1-669-201-9315, but may appear as “Unknown” or 740-587-6395.
Original Post:
Duo Security has received reports of Duo phone call authentication attempts not arriving to users’ devices and is currently investigating the situation. If you need to approve your login through Duo and have another option available, such as a Duo push, please use that if you are having trouble with the phone call option.
You can check the Duo status page directly at http://status.duo.com. This post will also be updated as more information becomes available.
DUO TIP: If you have a smartphone, ITS recommends using the Duo Mobile app – it is faster, more secure, and free. Please see this NetNotes post for details: https://netnotes.denison.edu/duo-push-faster-free-and-more-secure
For questions about Duo, please contact the ITS Help Desk at helpdesk@denison.edu or 740-587-6395.