CISSP Practice Exam 2026 – Complete Prep Guide

In the context of Kerberos, a realm refers to a logical Kerberos network. It is essentially a domain over which the Kerberos authentication service has authority. Each realm is defined by its own unique name and is capable of providing authentication services to users and services within that realm.

Kerberos operates on a principle of trust relationships between different realms, but each realm itself maintains its own database of users and services. This means that authentication requests from users within that realm are processed using the realm's key distribution center (KDC), which handles ticket granting and validation.

Other options do not capture the essence of what a realm is in Kerberos. A physical location for servers does not reflect the concept of logical boundaries or authority in authentication services. A specific encryption protocol does not define the structural or organizational aspect of how Kerberos operates. Similarly, while user authentication is a vital function of Kerberos, it does not specifically encapsulate the meaning of a realm, which is more about the scope and administration of authentication within a network.