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Courses and writing about computer networking, for people who have never touched it — worked through on your own computer, with nothing to buy.

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Courses on offer

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Basic Networking Fundamental

Beginner — no experience with any of this required

Build networks yourself across 17 exercises, in a free simulator from Cisco. No background needed, no equipment to buy, and one ordinary computer is enough.

7 parts·17 exercises·about 30 hours·taught to 15 cohorts so far

How data finds its way between machines, and what an IP address actually is
The two devices everything is built from — switches and routers — and setting one up
Splitting one network into several that stay apart, then letting them talk (VLANs)
Running a spare cable so the network survives a break, and bundling cables for speed
Letting data find its own way to a destination several hops away (routing)
Deciding who can reach what, and getting a whole office online (ACLs, NAT)
Handing out addresses automatically, and the newer kind replacing them (DHCP, IPv6)

No background needed
Nothing to buy
The software is free

Open to anyone, not only enrolled students. A place has to be requested first, and every request is decided by the instructor.

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Network Fundamental

A 29-lesson networking course, grouped into parts in reading order, free to read

Part 1 · Addresses and identity
1Internet Protocol — the layer that promises you nothing
2026-08-30 · 13 min read
What IP is, what is inside a packet header, how a machine decides where to send, and why a protocol that guarantees nothing became the foundation of the entire internet
Part 1 · Addresses and identity
2IPv4 subnetting — the bit boundary everyone recites and few understand
2026-08-30 · 13 min read
How a subnet mask works at the bit level, why it must be a boundary rather than a range of numbers, where it came from in 1985, and the cases where the usual rule about first and last addresses does not hold
Part 1 · Addresses and identity
3Subnet arithmetic by hand — six questions with one answer
2026-09-20 · 18 min read
Find the network ID, subnet mask, broadcast, host count, host range and next network with a single method, then go on to subnetting, route summarization and VLSM, with five exercises whose answers open on a click
Computed here Measured on a real machine

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CCAO-F exam prep

A course for the Claude Certified Associate – Foundations exam, built only from the official exam guide

Part 1 · Know the exam first
1What this course does, and what it will not do
2026-09-13 · 3 min read
This course is built from one document — the official exam guide. No dumps, no remembered questions, and the reason for that is written in the guide itself
Part 1 · Know the exam first
2What the exam looks like — the numbers from the official guide
2026-09-13 · 4 min read
Sixty items, a hundred and twenty minutes, a pass at 720 on a 100-1,000 scale, and seven domains that add to exactly 100% — with a source for every figure
Process and rules
Part 2 · The seven blueprint domains
3Domain 1 · Prompting and Task Execution
2026-09-13 · 3 min read
Fourteen percent, and the one domain most candidates assume is the whole exam. Its four objectives say otherwise
Judgment, not recall

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