Tutorials
Step-by-step beginner guides and on-the-job playbooks.
Beginner tutorials
- What is a computer network? A plain-English startWhat a network is, the kinds you use every day (LAN, WAN, the internet) and the devices that make them work. 5 min · Basics
- IP addresses explained simplyWhat an IP address is, public vs private addresses, and why IPv6 exists, explained with everyday comparisons. 6 min · Basics
- How DNS works: the internet's phonebookHow your device turns a name like example.com into an IP address, step by step, and what happens when DNS fails. 5 min · Basics
- DHCP: how devices get an IP address automaticallyHow a device joining a network is given its IP address, gateway and DNS automatically, and what to check when it fails. 4 min · Basics
- Modem, router, switch, access point: what each one doesThe everyday network devices explained in simple terms, so you know which box does what and where problems come from. 5 min · Basics
- TCP, UDP and port numbers in simple termsHow data is delivered reliably or quickly, and how port numbers make sure it reaches the right app on a device. 5 min · Basics
- NAT: how many devices share one internet addressHow your router lets every device at home or work use a single public IP address, and what that means for security. 4 min · Basics
- Wi-Fi basics and how to secure your wireless networkHow Wi-Fi works, 2.4 GHz vs 5 GHz, and a simple checklist to secure any home or small office wireless network. 5 min · Basics
- Cybersecurity basics: the CIA triadThe three goals behind every security decision (confidentiality, integrity and availability) with everyday examples. 4 min · Basics
- Strong passwords and multi-factor authenticationHow to create passwords that are easy to remember and hard to crack, why password managers help, and why MFA matters most. 5 min · Basics
- Phishing: how to spot fake emails and messagesThe warning signs of phishing emails, texts and calls, and exactly what to do if you clicked something. 5 min · Basics
- What is cloud computing? IaaS, PaaS and SaaS explainedWhat "the cloud" really is, the three service models with everyday examples, and the main deployment types. 5 min · Basics
- Virtualisation and virtual machines for beginnersHow one physical computer can run many virtual computers, why it matters, and how to use it for your own practice lab. 4 min · Basics
- MAC addresses: the name tag on every network cardWhat a MAC address is, how it differs from an IP address, how switches use it, and how to find yours. 5 min · Basics
- Network cables and Ethernet: what you plug in and why it mattersCopper Ethernet cables, categories (Cat5e to Cat6A), fibre, connectors and speeds explained simply, with tips for choosing the right cable. 5 min · Basics
- Firewalls for beginners: what they block and whyWhat a firewall does, how rules allow or block traffic, the difference between network and device firewalls, and why "deny by default" matters. 5 min · Basics
- Malware basics: viruses, ransomware and how to stay safeThe main types of malicious software (viruses, worms, trojans, ransomware, spyware), how they get onto devices and the habits that keep you safe. 5 min · Basics
- What is a server? Clients, servers and the services they runWhat servers and clients are, the common services servers run (web, email, file, DNS, DHCP), and where servers live today: on-site, data centres and the cloud. 5 min · Basics
- Backups made simple: the 3-2-1 ruleWhy backups matter, the 3-2-1 rule, full and incremental backups, sync versus backup, and why you must test a restore. 5 min · Basics
Step-by-step playbooks
- Playbook: "Users can't reach the internet"A step-by-step troubleshooting checklist for one of the most common support tickets, with Windows and Linux commands. 10 min · All levels
- Playbook: hardening a new access switchA practical security checklist for any new managed switch, with an example Cisco IOS configuration. 10 min · Intermediate