Networking fundamentals in the order a network engineer learns them, taught by doing: a browser Linux terminal for the commands, the OSI model layer by layer, IP addresses and subnet masks worked by hand, then DNS lookups, ports and sockets, ping, HTTP requests typed by hand and TLS on real hosts, and a lab where you address and fix a LAN. Free, with a certificate for each course.
Overview
Syllabus
- Learn Linux and the Command Line — Navigate the filesystem, manage files and permissions, chain commands with pipes, read logs. Every networking tool on this path is a terminal command, so the terminal comes first.
- The OSI Model — The seven layers and what actually lives at each one - frames, packets, segments, ports, protocols - with the TCP/IP model beside it. The vocabulary every later course, every job interview and every troubleshooting session uses.
- IP Addressing and Subnetting — IPv4 addresses, classes and CIDR, subnet masks, network and broadcast addresses, splitting a network into subnets and sizing them - worked by hand with instant checking until the arithmetic is automatic. The step most networking students fail and the one this path drills hardest.
- Networking with the Terminal — How hosts talk, names and DNS, ports and sockets, reachability checks, then HTTP typed by hand, curl in depth, sending data, HTTPS and TLS, and debugging authentication - on real hosts. This is how an engineer actually looks at a network from the command line.
- LAN Labs — Address the hosts on a LAN, get the masks right, add routers and gateways, troubleshoot what does not connect, then grow the office network and fix a broken branch. The lab where the previous three steps become one skill.
- Learn Docker & Containers — Images, containers and Dockerfiles, then the part most Docker courses skip: how containers get addresses, talk to each other and reach the outside world. The bridge from networking fundamentals into DevOps and cloud work.
Courses
-
Build, address and troubleshoot small networks in a terminal lab: hosts, switches and routers, cables, IPv4 addresses and masks, ARP, gateways, routing tables, and the classic faults that break real LANs.
Prerequisites:
- Comfortable running commands in a terminal
- Basic idea of IP addresses and subnet masks (our IP Addressing and Subnetting course covers it)
-
Learn how machines actually talk to each other, from the command line. Addresses and DNS, ports and sockets, whether a host is reachable, and HTTP by hand with curl: GET, POST, headers, status codes and HTTPS. Built for IT, support and backend work.
Prerequisites:
- Comfortable running commands in a terminal
- No networking knowledge required
-
How networks really talk, one layer at a time: the seven OSI layers, MACs and ARP, IP and routing, TCP, UDP and ports, encapsulation, and the full journey of a packet, with hands-on terminal walkthroughs.
Prerequisites:
- Comfortable running commands in a terminal
- No networking knowledge required
-
Master IP addresses from the bits up: binary, IPv4 anatomy, subnet masks, CIDR, subnetting drills, private ranges, network planning with VLSM, and a first look at IPv6. Practice everything in the terminal.
Prerequisites:
- Comfortable running commands in a terminal
- No networking knowledge required
-
A free, interactive Linux course for beginners. You type real commands into a browser-based Linux terminal on every lesson - files, permissions, pipes, bash - with a free certificate when you finish.
- Navigate the filesystem and manage files from the shell
- Read, search, and transform text with grep, sed, and pipes
- Compose commands with redirection and pipelines
- Use environment variables, permissions, and processes confidently
