Practical infrastructure guides for people who run systems
Backup, networking, monitoring and directory services, written from real consulting work rather than vendor brochures.
Topics
Backup and Recovery
How to design backups that actually restore: how many copies, which media, offsite rules, retention, and the restore tests that prove any of it works.
2 · Articles in this guide
Network Segmentation Guide: VLANs, Layers, and Access
How to divide a flat network safely: the three-layer model, VLANs and broadcast domains, inter-VLAN routing, port security, 802.1X, QoS, and documentation.
5 · Articles in this guide
Active Directory Guide: Architecture, DNS, Security
How Active Directory works in a real network: forests, OUs, FSMO roles, DNS, Group Policy, replication, security tiers, backup, and hybrid identity, in one map.
5 · Articles in this guide
Network Monitoring and Alerts: What to Watch and Alert On
How to monitor a small network without drowning in alerts: logs vs. metrics, trends vs. alarms, what to graph first, device health, and who owns each alert.
5 · Articles in this guide
Latest articles
- Active Directory Guide: Architecture, DNS, Security
Active Directory DNS: Forwarders, Reverse Zones, Split-Brain
Configure Active Directory DNS on Windows Server: forwarders, reverse lookup zones, conditional forwarders, and the split-brain setup that broke our own site.
17 min read
- Network Monitoring and Alerts: What to Watch and Alert On
How to Install Cacti on Ubuntu to Graph SNMP Traffic
Install Cacti on Ubuntu 24.04 with apt, add a switch over SNMP, and draw your first traffic graph, plus why there's no setup wizard and how to verify the graph.
14 min read
- Active Directory Guide: Architecture, DNS, Security
How to Join a Computer to an Active Directory Domain
Join Windows PCs and servers to Active Directory: DNS, time, and hostname prerequisites, Add-Computer, OU placement with redircmp, and the most common errors.
27 min read
- Network Monitoring and Alerts: What to Watch and Alert On
How to Set Up a Syslog Server on Ubuntu with rsyslog
Build a central syslog server on Ubuntu 24.04 with rsyslog: open UDP 514, split logs per sender, connect a switch, plan disk and rotation, and add TLS on 6514.
14 min read
- Active Directory Guide: Architecture, DNS, Security
Install Active Directory Certificate Services (AD CS)
Install Active Directory Certificate Services step by step: Enterprise Root CA setup, the four irreversible decisions, AIA/CDP, backup and end-to-end verification.
30 min read
- Network Segmentation Guide: VLANs, Layers, and Access
What Is a Port? TCP vs UDP and Connection Faults
What a port number does, how TCP and UDP differ, how to check open ports, and, when a connection won't form, which side the fault is on and how to prove it.
39 min read