DNS is the phone book of the internet: it turns a name people can remember into the address a machine needs. Most hosting and email problems come down to one wrong record. Here is what each common record does, in plain language, and when to use it.
A record
Points a domain to an IPv4 address such as 203.0.113.10. This is the record that sends yourdomain.com to your server. The most common record you will ever set.
AAAA record
The same idea as an A record, but for an IPv6 address. Add it only if your server has an IPv6 address and you want to serve visitors over IPv6.
CNAME record
Points one name at another name instead of an IP. For example, www.yourdomain.com as a CNAME to yourdomain.com. When the target's IP changes, the CNAME follows automatically.
Do not put a CNAME on your root domain (the bare
yourdomain.com). It conflicts with other required records. Use an A record on the root and a CNAME on subdomains.
MX record
Tells the internet where to deliver email for your domain. MX records point to mail servers and carry a priority number, where lower is tried first. If email is bouncing, the MX record is the first thing to check.
TXT record
Holds text used for verification and email security. The big three for deliverability live here:
- SPF lists which servers may send mail for your domain.
- DKIM adds a signature that proves messages were not tampered with.
- DMARC tells receivers what to do with mail that fails the checks.
Set all three and your mail is far less likely to land in spam.
NS record
Lists the nameservers that are authoritative for your domain. They decide where all your other records are read from. Changing nameservers moves DNS management to another provider. See How to point your domain to Vastrox.
TTL: how long records are cached
TTL (time to live) is how long resolvers cache a record before checking again. A lower TTL means changes apply faster at the cost of slightly more lookups. Lower it a day before a planned change, then raise it again once things are stable.
FAQ
A record or CNAME, which should I use?
Use an A record to point a name at an IP, which is required on the root domain. Use a CNAME to point a subdomain at another name that may change.
Why is my email going to spam?
Most often a missing or wrong SPF, DKIM or DMARC record. All three live in TXT records and tell other providers your mail is legitimate.
How long do DNS changes take?
Usually 30 minutes to a few hours, up to 48 worldwide. A lower TTL set in advance makes changes apply faster.
Not sure your records are right? Contact support and we will review your DNS with you.