#tcp

The TCP header has carried two flags since 2001: ECE and CWR. When both are lit in a SYN, the client...

net.ipv4.tcp_keepalive_time = 7200. The most familiar line in any sysctl file, and the most familiar...

I'll open this one with a confession from my own server. The VPS that runs this blog and a handful of...

The first time you hear about Multipath TCP it sounds too good: let a single TCP connection flow over...

Have you ever wondered what happens behind the scenes when you open a website? When we enter a...

My forwarder lost 3% of its messages. My laptop reported zero. CI reported zero. Staging lost...

"What happens when you type a URL and press enter?" is the most reused interview question in...

The wrong mental model For a long time I pictured a packet as a thing. A little sealed...

1. Why This Topic Matters The last post covered what's inside a TCP segment and how a...

Why an idle, healthy connection can still kill your next request — and how to fix it for good.

Layering and encapsulation are the whole trick — a compact map of the five-layer model with the details that matter in practice.

Have you ever looked at your device, seen “full bars” of Wi‑Fi strength, yet found yourself staring...