A server stack is the collection of software that forms the operational infrastructure on a given machine. In a computing context, a stack is an ordered pile. A server stack is one type of solution stack — an ordered selection of software that makes it possible to complete a particular task. Like in this post about Event 4771 (Bad Password Logon) Does not show proper client was one problem in server stack that need for a solution. Below are some tips in manage your windows server when you find problem about windows, active-directory, domain-controller, audit, eventviewer.
We are having issues with frequently locked out accounts.
We are having 4771 {Bad Password} events on our main DC.
Issue: Within the event, the client machine is not properly shown. Instead another DC is shown as client host name:
only in rare occasions the actual client host name is shown. What could be the cause for this?
What you are seeing is a logon take place at another Domain Controller, and then subsequently – as with all bad password attempts in Active Directory – the original logon server forwarding the authentication to the DC with the PDC Emulator FSMO role to double-check the password — to ensure that there wasn’t a password change that hadn’t been replicated yet, as the PDCe should be notified preferentially of any password changes.
The rare occasions when an actual client host name is shown, it is because the PDCe happens to be the original logon server of that request, and does not have to check with any other DC for confirmation.