Just to clarify, sounds like you are using NTLM with redirect mode, correct? Do you also have session cookie enabled? The authentication process when using NTLM is typically that when the user puts in their credentials, the credentials go to the PAN device, then to the user ID agent specified in the captive portal configuration, then the agent sends to the domain controller for authentication, then the User ID agent reports back to the PAN device, and permission is granted or denied. In light of this, it may or may not help to check your domain controller's logs to see if the authentication requests are getting there and denied or accepted. If the authentication is denied, then the user continues to be "unknown" and if you have forced captive portal policy for unknown users, then they shouldn't get allowed through. I believe you may also be able to see the captive portal denial in the System Log (Monitor tab). >>> Additionally, on Windows machines that are not part of the domains, or machines that are part of the domain but being logged onto locally, the last known authentication via captive portal is cached and no re-authentication via captive portal is being done - this was discovered trying to duplicate the no password error, it's been "cached" for 2 days. On this one I think you might need to check your session cookie. I'm wondering if you have your session cookie set to time out after 2 days. I think there are a few moving parts here to work through... You might want to call support and have them take a peek?
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