This article describes the Netdiag /fix switch. This switch may be useful for correcting issues with Domain Name Server (DNS) and domain controller tests.
The following tests are described:
If the computer is a domain controller, Netdiag verifies all the DNS entries in the Netlogon.dns file to determine if they are correct and updates the appropriate entries if there is a problem.
Domain Controller Tests
If the domain GUID cached in a local computer on your primary domain is different than the domain GUID saved in a domain controller, Netdiag tries to update the domain GUID on the local computer.