cs-username not showing in IIS logs in IIS7 classic mode

Question

I am running an asp.net application with forms authentication on IIS 7 in classic mode. Logging is turned on and the cs-username field is currently selected to be logged. However, the cs-username is always blank in the logs. Anyone have tips on how to determine the cause?

Answer 1

cs-username knows nothing about ASP.NET / forms authentication, and vice-versa... You have Anonymous access turned on in IIS, yes? That's why there is no cs-username output.

Answer 2

What Bryan says is true. In Classic mode, you go through double authentication processes. That is, IIS authenticates you first, and then ASP.NET authenticates you. In classic mode, the IIS Authentication is likely set to anonymous, in which case, IIS will log nothing in that field. If you turn on integrated pipeline, the authentication happens only once -- and within the IIS pipeline. That means that IIS can write data to the cs-username field.