Kerberos is the Microsoft authentication protocol that was introduced with the release of Windows Server 2000. It is the only authentication protocol that uses tickets, updated sequence numbers (USN), and is time stamped. The process of obtaining your service ticket is called a ticket granting ticket (TGT) session. It is important that the time on all servers and computers are within five minutes of each other; time can be synchronized by using a time source such as the Atomic Time clock. The Security+ exam looks at Stratum time servers.

Stratum Time Servers: There are three types of Stratum time servers, Stratum 1, 2, and 3. Stratum 1 is internal and Stratum 0 is external and the reference time source. The way to remember this is ...

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