SSL Inspection and Office 365

Lots of cloud endpoint URL’s break service flow if you enable SSL Inspection on the network devices between your client and the service. My most recent example of this Enterprise State Routing in Windows 10.

Microsoft have a list of URLs for the endpoints to their service, where they are categorised as Default, Allow or Optimize. The URLs that are Allow or Optimize should avoid SSL inspection.

The endpoint list is found at https://support.office.com/en-us/article/managing-office-365-endpoints-99cab9d4-ef59-4207-9f2b-3728eb46bf9a#webservice and the JSON for this can be downloaded, as well as a PowerShell script to return the IPs and URLs.

Within this JSON file you can look for the category and if the category is Allow or Optimize then ensure the matching URLs are not SSL inspected.