DNS Records
DNS records are the rows in a DNS zone that tell the internet what to do with a name: which IP, which mail server, or which verification string. Together they are the domain’s address book.
You edit them in the DNS panel controlled by the domain’s nameservers. Editing the wrong panel (a non-authoritative zone) is the most common reason a “change” never goes live.
Records You Will Use Most
| Type | Practical job |
|---|---|
| A | Name → IPv4 |
| AAAA | Name → IPv6 |
| CNAME | Alias to another name (not a raw IP) |
| MX | Mail delivery target |
| TXT | Free text: SPF, DKIM, Google verifies, etc. |
| NS | Authoritative nameservers (change carefully) |
| CAA | Which CAs may issue certificates |
Not every record is required. A simple site often needs an A record (or the host’s documented CNAME pattern) plus MX/TXT if you use domain email.
A Simple Pattern
- Apex A → hosting IP
wwwCNAME → apex (or its own A)- MX → mail provider
- TXT → SPF/DKIM so SMTP is less spammy
One wrong record does not always break everything — but a bad MX can kill email while the website still loads. Migration checklists should treat “web” and “mail” as separate tracks.
TTL and Propagation
Each record has a TTL. High values cache longer; low values make changes visible sooner. Before a major cutover, lower TTL first, then change A/MX. How that spreads worldwide is covered in domain propagation.
What to Watch For
- Edit the active zone (matching live nameservers)
- Respect TTL — changes are not always instant
- Do not delete verification TXT records you still need
- Apex CNAMEs are restricted on many classic DNS setups; follow your provider’s pattern
- Verify with DNS Lookup, ideally from more than one network
FAQ
How long until a new record works?
Minutes to many hours depending on TTL and resolver caches. MX mistakes feel painful quickly because mail fails.
Can I have multiple A records?
Yes for simple multi-IP setups, but it must be intentional. Accidental duplicates create confusing behavior.
My TXT value is very long — is that OK?
There are per-string length limits; long SPF/DKIM values are often split. Use the exact format your mail provider gives you.
Should I edit NS records inside the zone?
Rarely, unless you understand the impact. Registrar nameservers and zone NS records need to stay consistent.
Disclaimer: Hosting Wiki articles are prepared for educational and reference purposes. Hosting technology keeps evolving, so some technical details may change over time.