DNSProxy Cache Issues When Accessing SharePoint and OneDrive from 0365 Portal

[bwill]

Has anyone seen errors where your users access a SharePoint site and get a page "This page isnt working" or "secure connection failed page"?

We have an issue where users are accessing portal.office.com and when they click on OneDrive or SharePoint they get an error page.  What we found is that when we ping the url from the FortiGate we get a response unable to resolve hostname.  Once we do a diag test application dnsproxy 1, or clear dns cache, the user can access the site and I can ping from the FortiGate.

The odd thing is, this only happens to our links from the office portal for OneDrive and SharePoint.

Thanks in advance!

Bret

[bwill]

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