Every year someone declares Active Directory dead, and every year most enterprises keep running it. This part closes the series by looking upward: how traditional AD relates to Microsoft Entra ID (formerly Azure AD), what hybrid environments actually look like, what changed, what stayed the same, and where identity is heading.

Active Directory rarely fails loudly. It degrades — quietly, one unnoticed error at a time — until the symptoms surface somewhere far from the cause. This part covers the FSMO roles explained simply, what to check regularly, the early signs that AD is struggling, and the tools that do the checking.

Modern attacks on Active Directory rarely involve breaking anything — they involve logging in with credentials someone left lying around. This part covers privileged accounts, the principle of least privilege, why Domain Admin should almost never be used day to day, and the tier model explained simply.

Every administrator knows the call: a user is locked out again, for the fourth time today, and swears they typed the right password. This part covers why lockout policies exist, the surprising causes of lockouts beyond wrong passwords, how Fine-Grained Password Policies work, and how to trace a lockout back to its source.

Domains and forests are boundaries — but businesses do not stay inside boundaries. This part covers what trusts are, how one-way and two-way trusts actually work, and walks through the classic real-world scenario: two companies merging and needing to share resources long before their directories can be combined.

Why Active Directory cannot function without DNS, how clients use DNS to find Domain Controllers, and why so many AD problems turn out to be DNS problems in disguise.

How Active Directory replication keeps Domain Controllers in sync, what happens when it breaks, and how sites and site links work across offices.

Part 6 of the Active Directory Fundamentals series explains Group Policy, GPO processing order, Computer and User Configuration, LSDOU, default policies, loopback processing, inheritance controls, security filtering, and practical GPO design.

Active Directory · Part 5 Active Directory — Part 5 — Authentication & Kerberos In the earlier parts, we covered what Active Directory is, how domains and forests are structured,…

Part 4 of the Active Directory Fundamentals series explains user accounts, service accounts, Organisational Units, security groups, distribution groups, group scope, AGDLP, and why permissions should be assigned through groups instead of individual users.

Active Directory · Part 3 Active Directory — Part 3 — Domain Controllers Part 2 covered how Active Directory scales across domains, trees, and forests. Part 3 goes back inside…

Active Directory · Part 2 Active Directory — Part 2 — Domains, Trees & Forests Part 1 covered what Active Directory is and how it works inside a single environment.…

Active Directory · Part 1 Active Directory — Part 1 — What is Active Directory? A clear introduction to what Active Directory is, how it works, and why it remains…