401 Untracable for Azure Functions With OAUTH2

Question

I have several Azure Functions configured to use Azure Active Directory Authentication, where the client needs to send a valid Oauth2 token to be allowed to consume these functions. My problem is that in the case when the client sends an invalid token, or non at all, the function responds with a 401 as expected, but there would be no trace to this 401 in Azure, neither in the function logs, nor in App Insights. Where could I trace these 401s?

The Auth configuration of these functions are shown in the below snapshots

Answer 1

I assume your functions are validating the received JWT token against Azure AD. So the 401 error comes from there. Take a look at the Activity Logs:

https://docs.microsoft.com/en-us/azure/active-directory-b2c/view-audit-logs