Purconn

As Albert Einstein theorized time is relative, and the same applies to network environments of the Windows persuasion. Since Windows 2000 all Microsoft operating systems have used Kerberos Authentication to communicate over  an insecure network. It can have a few draw backs, one of which you are sure to come across at some stage, that is time. Kerberos uses the time of both the Server and Client computers as part of its ticket generation. If the Client computers time is not synchronized with the Server, the authentication will fail. This may manifest itself as failed windows logon, or a mapped drive which is no longer available and printers not being able to process print jobs from clients. The time on both the Client and Server must be within Five minutes by default.

I have found this issue most occurs with older computers with dead CMOS batteries and Accounts computers, for some reason best known to them Accounts personnel turn the time back or forward to process invoices. This is not an issue on a stand alone computer but on a networks Kerberos time stamps come into play and all sorts of strange things start to happen.

Kerberos is extremely complicated to diagnose at times but if you suspect it as the fault always start at the time.

Categories: IT