Networking Concepts
Networking Concepts (IT273) was a ten-week walk through the fundamentals of how networks are built and how data actually moves across them. I came in as a working sysadmin, so a lot of this was material I use every day rather than material I was seeing for the first time. That framing set my expectations: the value here was less about discovery and more about tightening up the vocabulary and reasoning I already lean on.
What the course covered
The arc started at the bottom with the OSI and TCP/IP models and stayed anchored to them the whole way through. Early weeks mapped protocols and data units to each layer, then built outward into physical and logical topologies, copper versus fiber cabling, and the tradeoffs each medium carries around distance, interference, and cost. From there it moved into the devices themselves, switches at Layer 2, routers at Layer 3, and load balancers, firewalls, and DNS servers sitting higher up the stack.
Later units got more practical. I worked through logical and physical network diagrams and what each is actually for, subnetting, DNS resolution and DNSSEC, wireless deployment and site-survey planning, and virtual desktop infrastructure. The course also spent real time on the governance side: the policy, standard, procedure, and guideline hierarchy, the CIA triad, and the ethics of network monitoring and deep packet inspection. It closed with a reflection on the Stuxnet documentary and what nation-state attacks mean for critical infrastructure.
What was useful
The most useful thread was troubleshooting methodology. Framing the choice between a bottom-up, layer-by-layer approach and pattern recognition from experience put language to something I already do by instinct, which makes it easier to explain to less experienced people. The governance units also landed well. The gap between a guideline and an enforced standard is exactly where I have watched security controls quietly fail in practice.
Honestly, the biggest win was the OSI model as connective tissue. Having every device, protocol, and failure mode hang off the same seven-layer frame is a clean way to reason about a network end to end, and it made the rest of the course cohere.