Computer Networks

If this were a book, this page is the table of contents. Each Part below is a chapter; each chapter links out to the concepts, designs, and platform notes that already exist elsewhere in this wiki instead of duplicating them. Unwritten chapters are listed as Planned rows, not empty files.

Parts

00 — Networking Fundamentals

Why networks exist and how the OSI/TCP-IP models frame everything after this Part — read this before any Part below, since the L4/L7 vocabulary from Chapter 3 recurs constantly.

• 1 — Why Computer Networks Matter — (stub)
• 2 — Data Communication Basics — (stub)
• 3 — Network Models — the OSI 7-layer model, why L4/L7 are the load-bearing layers in interviews, and a general protocol/L7-termination reference table
  • OSI Layer Model (L1-L7)
  • Protocol Inventory
• 4 — Network Devices — (stub)

01 — Ethernet and Local Networks

The link layer — framing, addressing, and switching on a single physical segment, before Part III introduces routing between segments.

• 1 — Ethernet — (stub)
• 2 — ARP — (stub)
• 3 — Switching — (stub)

02 — Internet Protocol (IP)

Addressing and routing between networks — IPv4/IPv6 header mechanics and how a packet actually finds its way across the internet.

• 1 — IPv4 — (stub)
• 2 — IPv6 — (stub)
• 3 — Routing — (stub)
• 4 — Routing Protocols — (stub)

03 — Transport Layer

TCP and UDP’s reliability, flow-control, and congestion-control mechanics, plus QUIC as the modern rewrite of the reliability model over UDP. See also sre/README.md Part 01 for the same protocols from the Linux-tooling angle.

• 1 — UDP — (stub)
• 2 — TCP Fundamentals — (stub)
• 3 — Reliable Transmission — (stub)
• 4 — TCP Optimization — (stub)
• 5 — QUIC — (stub)

04 — DNS

Name resolution end to end — record types, resolver hierarchy, and the caching/geo-routing levers that make DNS a performance and reliability control point, not just a lookup table.

• 1 — DNS Fundamentals — (stub)
• 2 — DNS Records — (stub)
• 3 — DNS Performance — (stub)

05 — HTTP Ecosystem

The application-layer protocols distributed systems actually speak — HTTP’s own version history, and the REST/GraphQL/gRPC/WebSocket API styles built on top of it. See also system-design/README.md Part 04 for the architectural-tradeoff angle on RPC style selection.

• 1 — HTTP Fundamentals — (stub)
• 2 — HTTP Versions — the connection-scaling argument behind preferring HTTP/2 (and therefore gRPC) at 100K+ agent fan-in
• 3 — REST — (stub)
• 4 — GraphQL — (stub)
• 5 — gRPC — call shapes, status-code backpressure, deadline propagation, and the connection-level load-balancing gotcha
• 6 — WebSockets — (stub)

06 — Security

Cryptography primitives through TLS/HTTPS mechanics to the authentication protocols and network-security controls that depend on them.

• 1 — Cryptography Fundamentals — (stub)
• 2 — TLS — TLS offload/termination architecture, the offload-vs-defense-in-depth trade-off, and where mTLS re-encryption fits
• 3 — HTTPS — (stub)
• 4 — Authentication Protocols — (stub)
• 5 — Network Security — (stub)

07 — Cloud Networking

Networking as configured in a cloud/Kubernetes environment — VPCs, Kubernetes’ own networking model, service mesh, load balancing, and CDNs. See also kubernetes/README.md Part 04 for CKA-level Kubernetes networking depth, and Envoy / patterns/09-cloud-native-patterns/01-sidecar for the service-mesh data-plane mechanics this Part’s Service Mesh chapter builds on.

• 1 — Virtual Networking — (stub)
• 2 — Kubernetes Networking — (stub)
• 3 — Service Mesh — (stub)
• 4 — Load Balancing — (stub)
• 5 — CDN — (stub)

08 — Performance Engineering

The levers available once a network is working correctly and the goal shifts to making it fast — connection reuse, compression, caching, and how to actually benchmark a network path.

• 1 — Network Performance — (stub)
• 2 — Connection Management — (stub)
• 3 — Compression — (stub)
• 4 — Caching — (stub)
• 5 — Network Benchmarking — (stub)

09 — Observability and Debugging

The practical toolkit for finding out what a network is actually doing — packet capture, Linux networking commands, and protocol-specific debugging tools.

• 1 — Packet Analysis — (stub)
• 2 — Linux Networking — (stub)
• 3 — DNS Debugging — (stub)
• 4 — HTTP Debugging — (stub)
• 5 — Kubernetes Network Debugging — (stub)

10 — Distributed Systems Networking

How networking failure modes show up specifically in distributed systems — RPC, message brokers, event streaming, and the CAP-theorem consequences of an unreliable network.

• 1 — RPC Systems — (stub)
• 2 — Message Brokers — (stub)
• 3 — Event Streaming — (stub)
• 4 — CAP and Networking — (stub)
• 5 — Cross-Region Communication — (stub)

11 — Networking Interview Mastery

A synthesis Part — common interview questions, real production incidents, and case studies from companies that operate networks at planet scale.

• 1 — Common MAANG Networking Questions — (stub)
• 2 — Production Incidents — (stub)
• 3 — Cloud Networking Case Studies — (stub)
• 4 — Networking Design Interviews — (stub)
• 5 — Review & Cheat Sheets — (stub)

12 — Appendix

Quick-reference tables and cheat sheets for use alongside every chapter above — protocol headers, addressing ranges, tool syntax, and terminology.

• 1 — Common Ports — (stub)
• 2 — HTTP Status Codes — (stub)
• 3 — TCP Flags — (stub)
• 4 — ICMP Message Types — (stub)
• 5 — CIDR Cheat Sheet — (stub)
• 6 — IPv4 Reserved Ranges — (stub)
• 7 — IPv6 Address Types — (stub)
• 8 — TLS Cipher Suites — (stub)
• 9 — DNS Record Types — (stub)
• 10 — Wireshark Filters — (stub)
• 11 — tcpdump Cheat Sheet — (stub)
• 12 — curl Cheat Sheet — (stub)
• 13 — Linux Networking Commands — (stub)
• 14 — Kubernetes Networking Commands — (stub)
• 15 — Cloud Networking Terminology — (stub)
• 16 — Common Interview Pitfalls — (stub)

Metadata

Author	Amit Singh
Scope	networks