What is DNS?

Computers use numbers; people use names. DNS translates between the two by telling your browser which IP address belongs to `beispiel.de`.

The records you need

A – Maps a name to an IPv4 address. The basic record for a website.
AAAA – Same for IPv6.
CNAME – Maps a name to another name, for example www to the bare domain.
MX – Where the emails go, regardless of where the website is located.
TXT – Text records used for verification and email authentication, such as SPF and DKIM to prevent forged senders.
NS – Which servers are responsible for this domain.

Why changes take time

Every record has a TTL, its lifetime in seconds. This tells caches how long they may keep the answer. A value of 86400 means a change can take a day to reach everyone.

If something does not work

First check whether DNS is responsible: does the name resolve to the expected address? On a Mac, run dig beispiel.de +short in Terminal. If it returns the correct address, check the web server, certificate and configuration.

Further in Technology

HTTP status codes explained – What 200, 301, 404 and 503 mean – and which of them cause you trouble.
301 or 302? – The decision takes five seconds – and the wrong one costs visibility.
Switch your website to HTTPS – In five steps – and with the two places where it almost always sticks.