DNS Record Types
The most common DNS record types and what they are used for
| Type | Purpose | Example |
|---|---|---|
| A | Maps a domain to an IPv4 address | example.com → 93.184.216.34 |
| AAAA | Maps a domain to an IPv6 address | example.com → 2606:2800:... |
| CNAME | Alias that points a name to another domain | www.example.com → example.com |
| MX | Mail server responsible for the domain | example.com → mail.example.com |
| NS | Authoritative name server for the domain | example.com → ns1.example.com |
| TXT | Arbitrary text, used for SPF, DKIM and verification | "v=spf1 include:_spf.example.com ~all" |
| SOA | Start of Authority: zone metadata and serial number | primary name server and admin email |
| PTR | Reverse DNS: maps an IP back to a hostname | 34.216.184.93.in-addr.arpa → example.com |
| SRV | Service locator: host and port for a service | _sip._tcp.example.com |
| CAA | Certificate Authority Authorization: which CAs may issue | 0 issue "letsencrypt.org" |
Email authentication records
These are published as TXT records and work together to protect a domain's email:
| Record | Purpose |
|---|---|
| SPF | Lists the servers allowed to send mail for the domain |
| DKIM | Signs outgoing mail so receivers can verify it was not altered |
| DMARC | Tells receivers what to do with mail that fails SPF or DKIM |