Notes on networks

Occasional write-ups on routing, latency and distributed systems.

Measuring path MTU without guessing

12 October 2026

A short note on why black-hole detection matters more than the nominal MTU, and how a handful of probes with the DF bit set can save an afternoon of debugging.

TLS handshakes and the cost of parallelism

28 September 2026

Browsers open several connections per origin; proxies that do the same behave very differently under load. Some measurements and a few rules of thumb.

What a relay can and cannot hide

9 September 2026

Forwarding bytes is cheap. Hiding traffic patterns is not. Notes from running a small TCP relay in front of an application server.