问题
My web app uses Windows authentication. All other authentication methods are disabled.
It works at first; User.Identity.Name returns "MYDOMAIN\myuser." However, if I wait 131 seconds (yes, I timed it, though I'm not sure it always takes exactly that long) and reload the page, User.Identity.IsAuthenticated = false and User.Identity.Name = "". At this point I can just reload the page and it works again, for another 131 seconds of inactivity.
Relevant parts of web.config:
<authentication mode="Windows" />
<authorization>
<deny users="?" />
</authorization>
<identity impersonate="false" />
...
<security>
<authentication>
<windowsAuthentication enabled="true" />
<anonymousAuthentication enabled="false" />
</authentication>
</security>
More information, possibly relevant:
My solution is deployed to two different IIS applications. The first one is for internal users; it just uses Windows authentication. The second one is for external users; it uses anonymous authentication (in the root folder only) and forms authentication. I'm only having problems with the internal site.
回答1:
The web.config file under the Account folder was allowing anonymous authentication (the one I posted with my question is the main web.config). Not sure how that happened, but removing it fixed the problem.
来源：https://stackoverflow.com/questions/12675593/user-identity-name-sometimes-blank-with-windows-authentication