DNS is the system that translates a readable name into a machine address. As long as everything works, nobody thinks about it. The day a site stops answering or emails vanish, understanding it becomes urgent. Here are the essentials.
Three roles not to confuse
The registrar is the company you rent the name from. A domain isn't bought outright: it's rented, in periods of at least a year.
The nameservers answer questions about your domain. They can sit at the registrar, at your host, or elsewhere.
The host runs the site. All three can be three different companies — that's common, and it's the source of most confusion.
The records you'll meet
| Type | What it does |
|---|---|
| A | Points a name at an IPv4 address |
| AAAA | The same, in IPv6 |
| CNAME | Makes one name an alias of another |
| MX | Says which server receives email |
| TXT | Holds free text: SPF, DKIM, verifications |
| NS | Designates the domain's nameservers |
Two rules avoid most mistakes: never put a CNAME at a domain's root, and an MX record points at a name, never at an IP address.
Propagation, that stubborn misunderstanding
"You have to wait 48 hours" is a phrase inherited from the 1990s. Today, a change is usually visible within minutes to a few hours.
What determines the delay is the TTL: how long each record may be cached by resolvers. A TTL of 3600 means a server that has already queried your domain will keep the old answer for at most an hour.
The administrator's trick: lower the TTL to 300 seconds the day before a migration, make the change, then raise it again once everything is stable.
The three records that decide your email's fate
If your messages land in junk, the cause is almost always here:
- SPF — a TXT record listing the servers allowed to send mail for your domain.
- DKIM — a cryptographic signature proving the message wasn't altered.
- DMARC — the rule telling receiving servers what to do when SPF or DKIM fails.
Transferring a domain: the procedure
- Unlock the domain at the current registrar.
- Request the authorisation code (auth code or EPP).
- Start the transfer at the new registrar with that code.
- Confirm the validation email.
- Wait: five days for generic extensions, often faster for
.fr.
Two things to know: a domain registered or transferred less than sixty days ago can't be transferred again, and a transfer usually adds a year to the expiry date. So you lose nothing.
One piece of advice that avoids nasty surprises
Put your domain's expiry date in your calendar, and enable automatic renewal. An expired domain can be recovered for a short window, often for a hefty fee — and sometimes it's bought within the minute by someone else.
Our domain search covers over a hundred extensions, with first-year and renewal prices shown side by side.