Track 01

Networking Fundamentals

From bits and signals to TCP, DNS, TLS 1.3, QUIC, and NAT — read packet captures, debug routing, write transports from scratch.

12 of 12 modules published

1.1

Bits, signals, and the physical layer

The physical layer from first principles: bits vs symbols, line encoding, clock recovery, noise, bandwidth, and why software engineers should care.

24 min read·introductory

1.2

Ethernet and MAC addressing

Ethernet frame format, MAC addressing, switching, ARP, broadcast domains, and the practical mechanics of a modern LAN.

20 min read·introductory

1.3

IPv4 addressing and subnetting deep dive

IPv4 from first principles: CIDR, prefix math, route aggregation, RFC 1918, VLSM, and the subnetting mistakes operators keep repeating.

22 min read·introductory

1.4

IPv6 fundamentals

IPv6 from first principles: address structure, SLAAC, Neighbor Discovery, extension headers, PMTUD, and the operational realities of dual stack.

20 min read·introductory

1.5

The IP forwarding plane

How a router actually forwards a packet: longest-prefix match, FIB lookup, adjacency resolution, TTL/Hop Limit, fragmentation, ICMP feedback, and the data/control/management plane split.

20 min read·intermediate

1.6

UDP, the simplest transport

UDP from first principles: datagram semantics, the 8-byte header, why DNS / QUIC / RTP / metrics protocols choose it, and when 'almost nothing' is the right answer.

16 min read·introductory

1.7

TCP at the wire level

TCP byte-by-byte: three-way handshake, state machine, sequence numbers, retransmission, window scaling, FIN vs RST. Read packet captures with confidence.

21 min read·intermediate

1.8

TCP congestion control

Why congestion control exists, how slow start and AIMD actually behave, what CUBIC and BBR change, and how bufferbloat ruins everything if you let it.

20 min read·intermediate

1.9

DNS — name resolution end to end

DNS from first principles: zones, delegation, recursive vs authoritative resolvers, the wire format, caching, DNSSEC, DoH/DoT/DoQ, and where privacy actually leaks.

21 min read·intermediate

1.10

HTTP/1.1, HTTP/2, HTTP/3 — the evolution

Why HTTP needed three rewrites in twenty years: pipelining's failure, HTTP/2's multiplexing, QUIC's leap to UDP, and the head-of-line blocking that connects all three.

17 min read·intermediate

1.11

TLS 1.3 handshake byte by byte

TLS 1.3 from first principles: ClientHello, key agreement, key schedule, certificate authentication, 0-RTT replay caveats, and what the wire still leaks.

17 min read·advanced

1.12

NAT, NAT traversal, and the end-to-end principle

Why NAT exists, how mapping/filtering/timeouts actually behave, what STUN/TURN/ICE are for, and why CGNAT compounds the problem IPv6 was supposed to fix.

16 min read·intermediate

For teams and consultants

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