Understand how data moves from your program to the wire. Parse Ethernet frames, IP packets, and TCP segments by hand. Send raw packets, build a TCP stack from scratch, and implement real protocols from their RFCs.
Start this track
Split an IPv4 Address into Octets
implement TCP IP from scratch
Networking starts at the wire and climbs the stack. Fundamentals cover packet layers, Ethernet, IPv4, TCP, UDP, and ICMP parsing. TCP/IP from scratch walks handshake, data transfer, retransmission, and congestion ideas. Raw sockets show ICMP and ARP without a framework. Protocol implementation builds DNS, HTTP, and other application protocols you actually use.
Search intent is strong for "implement TCP from scratch," "parse IP packet C," and "write a simple HTTP server." This track answers those with sequential tasks rather than a single giant project dump.
Comfort with C and sockets helps. Operating Systems context for processes and blocking I/O is useful but not required for early subtracks. You leave able to read a pcap and implement a minimal protocol without cargo-culting a library.
Trace packets through every network layer. Capture traffic with libpcap, parse Ethernet frames, IPv4 packets, TCP segments, and UDP/ICMP datagrams by hand.
Send and receive network packets without the OS doing anything for you. Craft raw ICMP, UDP, and ARP packets, capture traffic in promiscuous mode, and build a traceroute.
Build a TCP stack yourself. Implement UDP clients and servers with raw syscalls, the TCP 3-way handshake, data transfer with sequence numbers, retransmission, sliding windows, congestion control, and connection teardown.
Build real protocols from their RFCs. Implement a DNS resolver, HTTP/1.1 server with persistent connections, Redis RESP client, MQTT publisher, WebSocket frame parser, and NTP client.
Difficulty Progression