Blog
Thoughts on engineering, design, and building great products.
What Ansible Is and Why You Should Use It
Series opener: the configuration-management problem Ansible solves, why 'agentless' and 'idempotent' are the two most important keywords, the core concepts (control node, inventory, playbook, module, role), and the roadmap from basics to writing your own module.
How Networking Works: What Happens When You Open a Web Page
Series kickoff: trace a request's journey when you type a web address — from DNS resolution, the TCP handshake, TLS encryption, to HTTP and the response. Each leg is its own article ahead, assembled into a complete picture of networking.
The Layered Model: OSI and TCP/IP
The most important mental framework of the whole series: networking is designed as layers, each handling one job and relying on the layer below. Understand the 7 OSI layers, the 4 TCP/IP layers, and how data is encapsulated through each layer.
IP Addresses and Subnets
Every device on a network has an IP address. This article explains IPv4 structure, the network part and host part, the subnet mask and CIDR notation (/24), private (RFC 1918) vs public addresses, and why IPv6 exists.
The Link Layer: MAC, ARP and Switches
Within a local network (LAN), machines find and send data to each other by MAC address, not IP. This article explains MAC, why you need both MAC and IP, the ARP protocol that links the two addresses, and how a switch works.
Routing: Routers, Gateways and the Routing Table
How does a packet travel from your machine to a server on the other side of the world? This article explains routers, the default gateway, the routing table, and how a packet hops across each leg (hop) — observed for real with traceroute.
NAT and Private/Public IPs
Why does a whole household share one public IP out to the Internet? This article explains NAT — the mechanism by which a router translates private IPs into a public IP, tracks them by port, and why incoming connections from outside need port forwarding.