Labs & tutorials

Lab: Build an Active Directory Environment on Hyper-V

This lab builds a working Active Directory environment on Hyper-V: two domain controllers, a member server, and a client, on an isolated network. It is the foundation for practising Group Policy, certificate services, re...

• Create an isolated Hyper-V network with NAT for updates
• Promote a forest root domain controller and verify with dcdiag
• Add a second domain controller and confirm replication health
• Configure DHCP and a practical OU structure

PostgreSQL Index Strategy That Actually Works

Most "PostgreSQL is slow" tickets are an indexing problem, and most indexing problems come from adding indexes by intuition rather than by reading the plan. This is the method I use, and the specific index types that sol...

Diagnosing VoIP Call Quality Properly

"The calls are bad" is the least actionable ticket in unified communications. Bad how? For whom? In which direction? Almost every VoIP quality investigation that drags on for weeks does so because nobody separated the sy...

systemd Service Hardening

Most Linux services run with far more privilege than they need. systemd includes a sandboxing framework that removes most of it declaratively — no container runtime, no separate tooling, just directives in a unit file. T...