Networking

Core networking concepts for backend engineers and platform engineers — from physical bits to application protocols.

Files

File	Topics
osi-model.md	7 OSI layers, full HTTPS request flow (curl google.com), encapsulation/decapsulation, debugging by layer
tcp-udp.md	TCP 3-way handshake, 4-way teardown, state machine, flow control, congestion control (CUBIC/BBR), TIME_WAIT, UDP, when to use each
tls-encryption.md	Symmetric vs asymmetric, SSL history, TLS 1.2 (2 RTT), TLS 1.3 (1 RTT), certificate chain, certificate validation, debugging with openssl
http-versions.md	HTTP/1.0 → HTTP/3, HOL blocking, binary framing, status codes, methods, important headers, caching (ETag), CORS, QUIC wire-level mechanics, WebSocket upgrade handshake/frame format
grpc-graphql.md	gRPC architecture, Protobuf encoding, 4 streaming modes, connection flow, status codes; GraphQL SDL, query vs REST, N+1, DataLoader
grpc-deep-dive.md	Protobuf wire format internals, all 4 streaming modes with full code, interceptors, deadline propagation, health checking, client-side load balancing, gRPC-Web, error code mapping
linux-networking.md	Linux packet RX/TX path, netfilter hooks, conntrack, network namespaces, veth pairs, SO_REUSEPORT, debugging commands
bgp-routing.md	Autonomous systems, path-vector routing and path selection (LOCAL_PREF/AS-PATH/MED), why anycast works, route leaks/hijacks, RPKI
load-balancers.md	L4 vs L7, algorithms, health checks, sticky sessions, TLS termination, AWS ALB/NLB, LCU/NLCU, GCP GLB, nginx, HAProxy, common issues
cdn.md	CDN internals, edge PoPs, cache hierarchy, Cache-Control headers, CloudFront, Cloudflare, GCP CDN, WAF, debugging
nslookup-vs-curl.md	DNS resolution vs HTTP request path, when nslookup succeeds but curl fails, layered debugging
zero-trust.md	Zero Trust vs perimeter security, BeyondCorp model, GCP Identity-Aware Proxy (IAP), mTLS + Istio AuthorizationPolicy, PSC + IAP + mTLS composition, debugging

Read Order

osi-model.md         → understand the full picture
tcp-udp.md           → transport layer (TCP state machine, TIME_WAIT)
tls-encryption.md    → TLS 1.2 vs 1.3, certificate validation, mTLS
http-versions.md     → HTTP/2 multiplexing, status codes, headers, QUIC, WebSocket
grpc-graphql.md      → modern API protocols built on top
grpc-deep-dive.md    → gRPC wire-level internals and production concerns
linux-networking.md  → kernel packet path, netfilter, conntrack, namespaces
bgp-routing.md       → how networks actually route between each other
load-balancers.md    → L4/L7, algorithms, AWS ALB/NLB, GCP, nginx, HAProxy
cdn.md               → edge PoPs, caching, CloudFront/Cloudflare/GCP CDN
nslookup-vs-curl.md  → layered debugging when DNS works but HTTP fails
zero-trust.md        → ZTNA, BeyondCorp, IAP, mTLS + PSC composition

Networking

Networking

Files

Read Order

Pages in this section