Csc5113c

CSC5113C does something crueler—and far more educational. It forces you to implement the protocols, then immediately break them.

I was debugging a "simple" TCP congestion control algorithm for my CSC5113C project. The assignment was straightforward: modify the Linux kernel’s TCP stack to improve throughput over high-latency links. Straightforward, until it wasn't. csc5113c

One week you’re coding a reliable data transfer protocol over UDP (think: TCP from scratch, but sadder). The next week, your lab partner is tasked with launching a selective ACK dropping attack against your implementation using Scapy. CSC5113C does something crueler—and far more educational

There, nestled between legitimate ACK packets, was a series of RST (reset) packets with a TTL that didn’t match the rest of the stream. Someone—another student in the class, probably working on the offensive security track—had quietly ARP-poisoned my subnet. They weren't stealing data. They were just injecting resets to watch my retransmission timer explode. The next week, your lab partner is tasked

In CSC5113C, the network isn't a series of tubes. It's a gladiator arena. Most networking courses teach you the OSI model, TCP state diagrams, and BGP routing. You memorize port numbers. You calculate checksums. You yawn.

By the final project—where you must design a zero-trust microsegmentation policy for a mock cloud environment—you’re no longer thinking about bandwidth or latency. You’re thinking: If I were the attacker, where would I sit? Only if you enjoy the feeling of your certainties being unplugged.

The first time you see a DNS exfiltration tunnel—where someone encoded /etc/passwd into subdomain requests—it feels like magic. By the end of the lab, you realize it’s just math. Clever, terrifying math.