Active Directory
Windows Server 2025 domain services, users, computers, DNS, authentication and Group Policy.
IT Infrastructure • Homelab • Cybersecurity
I’m Mark Gray. This site documents my hands-on journey through Windows Server, Active Directory, networking, Linux, Microsoft 365, automation and cybersecurity.
What this site is about
My homelab is where I develop practical infrastructure and security skills by building systems, troubleshooting faults, testing controls and documenting what I learn.
Rather than simply listing technologies, this portfolio focuses on the work behind them: the problems I encountered, the decisions I made and the results I achieved.
Homelab
My lab combines Windows, Linux, network segmentation, virtualization and cloud services so I can practise realistic administration, troubleshooting and security scenarios.
Windows Server 2025 domain services, users, computers, DNS, authentication and Group Policy.
Segmented networks, OPNsense firewalling, routing, DNS control and attacker/target lab zones.
Debian-based workstation, KVM/libvirt virtual machines, Linux services and command-line tooling.
Entra ID, Microsoft 365 administration and hybrid identity work connecting on-premises AD to the cloud.
Lab Architecture
A segmented homelab combining on-premises infrastructure, authorised security testing, monitoring, and Microsoft 365 / Entra integration.
Featured Projects
Connecting an on-premises Windows Server Active Directory environment to Microsoft 365 using Entra Connect, while troubleshooting identity, UPN and synchronization issues.
A segmented attacker and production environment used for authorised reconnaissance, service enumeration and defensive analysis against a Windows domain controller.
A Python-based evidence analysis workflow using the OpenAI API to correlate Nmap, LDAP, DNS and SMB evidence and produce structured technical reports.
Cybersecurity Journey
My focus is on understanding how systems are attacked, how those attacks appear in logs and network traffic, and how infrastructure can be configured to reduce risk.
Foundation
Built practical knowledge of addressing, DNS, routing, Windows administration and Linux fundamentals.
Build
Created segmented networks, Windows Server infrastructure, client systems, Linux hosts and firewall controls.
Test
Practised reconnaissance and enumeration using tools such as Nmap, Kerbrute, smbclient and ldapsearch.
Defend
Investigated logs, firewall events and network traffic to understand how suspicious activity is detected.
Hands-on Cybersecurity Training
My TryHackMe page brings together my public training profile, practical learning activity and achieved certifications, including the Pre Security (SEC0) certification.
Skills
About Me
This portfolio will continue to grow as I complete new lab projects, security exercises, Microsoft 365 work and technical write-ups.