The Domain Name System (DNS) is the internet's directory. When someone types your domain or sends you an email, DNS tells their computer where to go. Mistakes here take websites offline and stop mail, so it is worth understanding the basics.
The records you will meet
- A record: points a name, such as yourbusiness.com, to an IPv4 address.
- AAAA record: the same for an IPv6 address.
- CNAME: makes one name an alias for another, for example www pointing to yourbusiness.com, or a subdomain pointing to a third-party service.
- MX records: tell the world which servers receive email for your domain.
- TXT records: hold text used for verification and email security, including SPF, DKIM and DMARC.
- NS records: name the servers that are authoritative for your domain's DNS.
TTL: how long answers are cached
Every record has a time to live, the number of seconds other servers may cache it. Long TTLs reduce lookups; short TTLs make changes take effect quickly. Lower the TTL before a planned change such as a migration.
Common mistakes
- Changing nameservers without first copying every existing record, which silently breaks email or verification.
- Several SPF records instead of one combined record.
- Forgetting the MX records when moving a website, so mail goes to the wrong place.
- Leaving old records pointing at services you no longer control, which can let others take over a subdomain.
Protect the keys to your domain
Whoever controls your registrar account and DNS controls your website and email. Use a strong password and two-factor authentication on the registrar account, keep contact details current, and turn on registrar lock to prevent unauthorised transfers.
How IDX helps
IDX registers and transfers domains and includes DNS zone management with our hosting, so your website, email and verification records live in one place. Our team can review your DNS before a migration so nothing is missed.
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