What is Active Directory?

Active Directory (AD) is a directory service developed by Microsoft, used in Windows networks to centrally manage users, computers, and permissions.

What is Active Directory?

AD is a centralized database containing information about every user and computer in the network. The main server running it is called a Domain Controller (DC).

Forest
└── Domain (cyberah.local)
    ├── Users
    ├── Computers
    ├── Groups
    └── OUs (Organizational Units)

How Does Kerberos Work?

Kerberos is the primary authentication protocol in Active Directory, based on a ticket system.

Authentication Flow

1. The user requests a ticket from the KDC (Key Distribution Center)
2. The KDC verifies identity and issues a TGT (Ticket Granting Ticket)
3. The user uses the TGT to request service tickets

# View current tickets
klist

# Request a ticket
kinit user@DOMAIN.LOCAL

What is the Ticket System?

Two main ticket types in Kerberos:

Note: The TGT is encrypted with the krbtgt account’s key and cannot be read directly.