Fundamentals of Network Engineering

Explore how client-server architecture separates heavy workloads to beefy servers, with lightweight clients calling them through remote procedure calls for scalable, multi-component applications.

Understand the OSI seven-layer model and how applications, proxies, and network devices map to it; explore why standardization enables agnostic, decoupled networking and media-wide deployment.

Demonstrates host-to-host communication from MAC addresses to IP routing, explains why IP addresses are needed, and covers networks, subnet masks, routers, gateways, and ports.

Explore the anatomy of the IP packet, including the header and data, and the impact of 20-byte headers, up to 60-byte options, MTU, fragmentation, TTL, and ICMP.

Explore ICMP, the layer 3 protocol behind ping and traceroute, including TTL, fragmentation, and destination unreachable messages, and how ICMP informs reachability without ports.

Explore how the address resolution protocol maps ip addresses to mac addresses to deliver frames, using arp tables and broadcast requests in local networks.

Understand UDP, a lightweight stateless layer on top of IP that uses ports to address host processes, enabling simple, no-connection data delivery for video streaming and WebRTC.

Explore the udp data structure by examining its 8-byte header, 16-bit source and destination ports, and how the payload sits in an ip packet, using DNS as an example.

learn to build a UDP server in Node.js using the dgram library, binding to localhost port 5500 on IPv4, handling incoming messages via a message event, and testing with netcat.

build a udp server in c by creating and binding an ipv4 socket on port 5501 to receive datagrams into a 1024-byte buffer and print the source address and data.

Demonstrate capturing UDP traffic with tcpdump, issuing a DNS query to 8.8.8.8, filtering for UDP port 53, and inspecting UDP datagram and DNS query IDs.

Explore the transmission control protocol, a reliable, stateful transport that uses ports and a three-way handshake to establish connections, ensure ordered delivery, and manage flow and congestion.

Explore the tcp segment anatomy: 20-byte header, optional fields, 16-bit ports, sequence and acknowledgement numbers, flow control windows, and flags such as syn, ack, and fin, plus mss/mtu context.

Explore how flow control avoids receiver overload using the receiver window, sliding window, and window scaling, to manage TCP data and acknowledgements.

Analyze how congestion control manages network capacity using the congestion window, slow start, and congestion avoidance, while accounting for receiver window and ECN signals to reduce drops.

Learn how NAT lets private devices share a public IP despite IPv4 limits by mapping private addresses and ports via a gateway, enabling port forwarding and layer four load balancing.

Explore TCP connection states and the four way handshake, including fin, time wait, and last acknowledgement, and discuss strategies to manage lingering connections and avoid session resumption attacks.

Analyze the pros and cons of tcp, including guaranteed delivery, connection setup, flow and congestion control, and the head-of-line blocking and header overhead that affect latency.

Build a TCP server in Node.js using the net module, log handshake, capture remote address and port, send a hello, and handle multiple connections on port 8800.

Build a tcp server in c by binding, listening, and accepting connections. Create new sockets for each client, send a hello message, and leverage backlog and multithreading.

Explore how networking concepts bridge fundamental theory to daily practice, examining performance, latency, and effectiveness through real-life examples, and compare tcp and udp configurations across client and back-end applications.

Explore tcp fast open, sending data during the handshake with a pre-authenticated cookie, and learn how this reduces latency after dns and tls.

Explore tcp head of line blocking: a single missing segment stalls the entire stream, and selective acknowledge could help when multiple streams share one tcp connection.

Explain the difference between proxy and reverse proxy, and how proxies enable anonymity, caching, logging, and load balancing for APIs, gateways, and microservices.

Explore how devices use MAC addresses and data link logic to send and filter frames, then learn how IP routing uses subnets, gateways, and routing tables to reach across networks.

Explore docker networking by building custom networks, connecting containers, and testing communication with curl, ping, and DNS, including gateway, bridge, and route concepts.

Learn to use Wireshark to sniff UDP packets, capture traffic, filter for a DNS UDP packet to 8.8.8.8:53, and read frame, IP, UDP details including MAC, TTL, and payload.

Demonstrate tcp http capture with wireshark by curling example dot com and examining the handshake, http get request, and basic ip/tcp headers.

The Linux kernel maintains a syn queue and an accept queue for each listening socket, allowing multiple processes to accept connections with FIFO ordering and occasional contention.