A small reference notebook

Notes

Choose a subject below. Each note can be read on its own.

Keep names and addresses separate

A name is a label that people can keep while an address changes. A DNS lookup connects those two ideas. Keeping them separate makes a connection problem easier to describe: first record the name you requested, then the address your resolver returned. Neither fact, by itself, tells you whether the service at that address is healthy.

What a verified connection tells you

A certificate check relates a connection to the name requested by the client. It is useful to preserve that check when investigating a failure. Removing the check can make one error disappear while losing the very property being examined.