Blog
Thoughts on engineering, design, and building great products.
Tracing a Request End to End
The final article: putting everything together to trace a complete https:// request — from DNS resolution, routing, the TCP handshake, TLS encryption, to HTTP and the response — with real per-phase timing. Plus a series wrap-up.
Basic Networking on Linux
View IP addresses and routing (ip), check which ports are listening (ss), test connections (ping, curl), and understand name resolution (DNS, /etc/hosts). Enough to diagnose most networking issues on a server.
Networking in Docker: Bridge, veth and Port Mapping
How containers reach each other and the outside world: the network drivers, the default bridge and the veth mechanism, port publishing, and why a user-defined network lets containers call each other by name while the default bridge does not.
Swarm: Overlay Network and Routing Mesh
How do containers on different nodes talk to each other, and why does publishing one port make it reachable from any node? This article explains the overlay network (VXLAN), service discovery via VIP, and the routing mesh.
VPC and Security Group: Networking and Basic Firewalling on AWS
Understand VPC, public/private subnets, route tables, and Security Groups. Know why your server lets some in and not others, and how to tighten access correctly.