Lab 02: Domain Join and Authentication

Overview

In this lab, I configured CL1 to use DC1 for internal DNS, joined the workstation to the corp.nietz.co.uk domain, and confirmed that domain authentication and Group Policy processing were working correctly.

This builds directly on Lab 01, where DC1 was configured as the first domain controller for the environment.

Objective

The objective was to convert CL1 from a standalone Windows client into a managed domain workstation that can authenticate against Active Directory and receive domain policy.

Environment

Configuration

1. Client DNS Configuration

I configured CL1 to use DC1 as its preferred DNS server so the workstation could resolve Active Directory records from the internal domain.

Context: Domain join depends on DNS. CL1 must query DC1, not router DNS or public DNS, to locate domain controllers and Active Directory service records.

2. Network Connectivity Validation

I confirmed that CL1 could reach DC1 across the lab network before attempting the domain join.

Context: Basic network reachability must work before authentication, domain join, Group Policy, or file services can operate reliably.

3. Domain Join

I joined CL1 to the corp.nietz.co.uk domain using domain credentials.

Context: Joining the domain registers the workstation in Active Directory and creates the secure trust relationship required for domain sign-in.

4. Domain Login

I restarted CL1 and confirmed that domain authentication worked by signing in with a domain account.

Context: A successful domain login confirms that CL1 can authenticate against the domain controller after joining the domain.

5. Computer Object Validation

I confirmed in Active Directory Users and Computers that the CL1 computer object was created in the default Computers container.

Context: The computer object proves that the workstation was registered in Active Directory and is now managed as a domain member.

6. DNS and Domain Controller Discovery

I validated domain DNS resolution and domain controller discovery from CL1.

Context: DNS and domain controller discovery are required for logon, Group Policy, Kerberos, LDAP, and domain resource access.

7. Group Policy Validation

I confirmed that CL1 processed baseline domain Group Policy after the domain join.

Context: Group Policy processing confirms that the workstation is receiving domain management settings and is ready for later policy-based configuration labs.

Validation

The lab was validated when CL1 successfully joined corp.nietz.co.uk, allowed domain sign-in, appeared in Active Directory Users and Computers, resolved the domain through DC1, discovered DC1 as the domain controller, and processed baseline Group Policy.

Key Technical Outcomes

This lab demonstrated the relationship between workstation DNS configuration, domain controller discovery, secure channel creation, Active Directory computer objects, and Group Policy processing during a Windows domain join.

It also reinforced that domain join failures are often caused by DNS or domain controller discovery problems rather than the domain join wizard itself.