The OSI Model
The 7-layer reference model — a mental framework for networking.
Networking
Net 01 — Fundamentals3 articles
The TCP/IP Model
The 4-layer model that actually runs the internet.
Encapsulation
How data gets wrapped at each layer for transmission.
Net 02 — Ethernet & Switching3 articles
Ethernet
Layer 2 — the protocol that connects everything on a LAN.
Switching
How switches learn, forward, and filter traffic.
VLANs (802.1Q)
Logical network segmentation at Layer 2.
Net 03 — IP & Routing4 articles
IPv4
32-bit addressing, subnetting, and the protocol that built the internet.
IPv6
128-bit addresses — solving exhaustion and simplifying the protocol.
IP Routing
How routers make forwarding decisions.
Dynamic Routing (OSPF & BGP)
OSPF, BGP, and how the internet finds paths.
Net 04 — TCP & UDP4 articles
TCP Deep Dive
Reliable, ordered, connection-oriented transport.
TCP State Machine
Connection lifecycle from LISTEN to CLOSED.
UDP
Connectionless, fast, no guarantees.
Ports & Sockets
How the OS multiplexes network connections.
Net 05 — DNS3 articles
How DNS Works
The complete resolution process — from query to answer.
DNS Record Types
A, AAAA, CNAME, MX, TXT, SRV, and more.
Advanced DNS
Split-horizon, anycast, DNSSEC, and encrypted DNS.
Net 06 — HTTP & TLS4 articles
HTTP (1.1 / 2 / 3)
The application protocol of the web — from 1.1 to 3.
TLS
Transport Layer Security — encryption, authentication, integrity.
mTLS & Certificate Management
Mutual authentication and practical certificate operations.
Web Servers
What they do, how they handle connections, and how they fit in the stack.
Net 07 — Firewalls, NAT & VPN3 articles
Net 08 — NAT Traversal & Tailscale5 articles
NAT Types & Behavior
How different NATs affect connectivity — RFC 4787 classification.
STUN, TURN & ICE
The protocols that punch through NATs.
Tailscale Architecture
How Tailscale achieves direct, encrypted connections through NATs.
Tailscale Features
MagicDNS, ACLs, subnet routers, and the full feature set.
NAT Traversal Deep Dive
How direct connections happen through NATs — based on Tailscale's "How NAT Traversal Works".
Net 09 — Linux Internals3 articles
Namespaces & Virtual Interfaces
The kernel primitives that make container networking possible.
Netfilter Internals
The kernel framework behind iptables, conntrack, and NAT.
iproute2 & Traffic Control
Modern Linux networking tools: ip, tc, and sysctl knobs.
Net 10 — eBPF & XDP3 articles
eBPF Fundamentals
Sandboxed programs in the kernel — the programmable data plane.
XDP & tc-bpf
Programmable packet processing at line rate.
Cilium
eBPF-powered networking for Kubernetes.
Net 11 — Cloud-Init3 articles
Cloud-Init Basics
The industry standard for instance initialization.
User-Data & Cloud-Config
Configuring instances with YAML and scripts.
Network Configuration
Configuring networking via cloud-init and Netplan.
Net 12 — Container Networking2 articles
Docker Networking
Container networking from the kernel up.
CNI (Container Network Interface)
The CNCF standard that Kubernetes uses for pod networking.
Net 13 — Kubernetes Networking4 articles
Pod Networking
How every Pod gets a unique, routable IP.
Services
Service discovery, load balancing, and the kube-proxy implementation.
Ingress & Gateway API
L7 routing — exposing services to the outside world.
Network Policies
Pod-level firewall rules and service mesh basics.
