Introduction
DNS (Domain Name System) records are instructions stored in authoritative DNS servers that provide information about a domain. Each record type serves a specific purpose. This guide explains the most common DNS record types and when to use them.
A record (Address)
Maps a domain name to an IPv4 address.
| Host | Type | Value | Example use |
|---|---|---|---|
@ |
A | 203.0.113.10 |
Point your domain to your server |
www |
A | 203.0.113.10 |
Point www.yourdomain.com to your server |
AAAA record (IPv6 Address)
Same as an A record, but maps a domain name to an IPv6 address.
| Host | Type | Value | Example use |
|---|---|---|---|
@ |
AAAA | 2001:0db8:85a3::8a2e:0370:7334 |
Point your domain to an IPv6-enabled server |
CNAME record (Canonical Name)
Creates an alias that points one domain name to another. The target must be a domain name, not an IP address.
| Host | Type | Value | Example use |
|---|---|---|---|
www |
CNAME | yourdomain.com |
Make www resolve to the same place as the root domain |
blog |
CNAME | mysite.wordpress.com |
Point a subdomain to an external service |
Important: A CNAME record cannot coexist with other record types for the same hostname. You cannot set a CNAME on the root domain (@) if you also have MX or TXT records there.
MX record (Mail Exchange)
Specifies which mail server(s) should receive email for your domain. The priority value determines the order in which servers are tried (lower number = higher priority).
| Host | Type | Value | Priority | Example use |
|---|---|---|---|---|
@ |
MX | mail.yourdomain.com |
10 | Primary mail server |
@ |
MX | backup.yourdomain.com |
20 | Backup mail server |
TXT record (Text)
Stores arbitrary text data. Commonly used for domain verification and email authentication.
Common uses
| Purpose | Host | Example value |
|---|---|---|
| SPF (email auth) | @ |
v=spf1 include:_spf.google.com ~all |
| DMARC | _dmarc |
v=DMARC1; p=reject; rua=mailto:dmarc@yourdomain.com |
| Domain verification | @ |
google-site-verification=abc123... |
| DKIM | selector._domainkey |
v=DKIM1; k=rsa; p=MIIBIjANBg... |
SRV record (Service)
Specifies the hostname and port for specific services. Used by protocols like SIP, XMPP, and Microsoft 365.
| Format | Example |
|---|---|
_service._protocol.name |
_sip._tcp.yourdomain.com |
The value includes priority, weight, port, and target: 10 5 5060 sipserver.yourdomain.com
NS record (Name Server)
Delegates a domain or subdomain to a set of DNS servers. These records determine which servers are authoritative for your domain.
| Host | Type | Value | Example use |
|---|---|---|---|
@ |
NS | ns1.yourhostingprovider.com |
Set your domain's name servers |
Important: Changing NS records at your registrar redirects all DNS queries for your domain. Only modify these if you are intentionally changing DNS providers.
PTR record (Pointer / Reverse DNS)
Maps an IP address back to a domain name (the reverse of an A record). PTR records are essential for email deliverability — many mail servers reject email from IPs without a valid reverse DNS entry.
PTR records are typically managed by your hosting or IP provider, not in your domain's DNS zone.
CAA record (Certification Authority Authorization)
Specifies which certificate authorities (CAs) are allowed to issue SSL/TLS certificates for your domain.
| Host | Type | Value | Example use |
|---|---|---|---|
@ |
CAA | 0 issue "letsencrypt.org" |
Only allow Let's Encrypt to issue certificates |
Quick reference
| Record | Purpose | Points to |
|---|---|---|
| A | Domain → IPv4 | IP address |
| AAAA | Domain → IPv6 | IPv6 address |
| CNAME | Alias → another domain | Domain name |
| MX | Email routing | Mail server hostname |
| TXT | Text data (SPF, DKIM, verification) | Text string |
| SRV | Service location | Host + port |
| NS | DNS delegation | Name server hostname |
| PTR | Reverse DNS (IP → domain) | Domain name |
| CAA | CA authorization | CA domain |