DNS Record Types
A comprehensive reference for the most common DNS record types — what each does, how it's structured, and when to use it.
Common DNS Records
Select a record type for syntax, examples, and configuration guidance
Maps a hostname to an IPv4 address. The most fundamental DNS record — the final answer for most web traffic.
Maps a hostname to an IPv6 address. Required for dual-stack deployments as IPv4 address space exhaustion continues.
Creates an alias from one hostname to another canonical name. Resolvers follow the chain until reaching an A/AAAA record.
Specifies the mail server(s) responsible for accepting email for a domain, with priority values for redundancy.
Stores arbitrary text data. Used for SPF, DKIM public keys, DMARC policies, domain verification tokens, and more.
Identifies the authoritative nameservers for a domain. These records define who has final authority for the zone.
Start of Authority — contains zone metadata: primary nameserver, admin contact, serial number, and timing parameters.
Maps an IP address back to a hostname. Essential for mail server reputation, security logging, and network diagnostics.
Locates services by protocol and port — used by SIP, XMPP, IMAP autodiscovery, Kubernetes, and other service-discovery systems.
Restricts which Certificate Authorities are permitted to issue TLS certificates for your domain — a key defense against misissued certificates.
Record Type Cheat Sheet
| Type | Category | Can appear at apex (@)? | Multiple records? | Points to |
|---|---|---|---|---|
| A | Address | Yes | Yes (load balance) | IPv4 address |
| AAAA | Address | Yes | Yes (load balance) | IPv6 address |
| CNAME | Alias | No (use ALIAS/ANAME) | No | Hostname |
| MX | Yes | Yes (priority) | Hostname (not IP) | |
| TXT | Text | Yes | Yes | Quoted text string(s) |
| NS | Delegation | Yes (zone NS) | Yes | Hostname |
| SOA | Zone | Yes (required) | No (exactly one) | Zone metadata |
| PTR | Reverse DNS | N/A (in-addr.arpa) | No | Hostname |
| SRV | Service | No | Yes (priority/weight) | Priority + weight + port + hostname |
| CAA | Security | Yes | Yes | CA hostname or report URL |
Full List of DNS Record Types
Beyond the common types covered here, DNS defines many additional record types
The ten record types on this page cover the vast majority of real-world DNS deployments, but the DNS protocol defines well over 80 resource record types in total — from legacy types that predate the modern internet to specialized types for DANE, DNSSEC key material, and experimental uses.
The authoritative list of all currently assigned DNS resource record types is maintained by IANA (Internet Assigned Numbers Authority) in the DNS Parameters registry. Each entry shows the type number, mnemonic, and the defining RFC.
The process for registering new DNS record types is defined in RFC 6895 — new types require IETF review and must specify their RDATA format, presentation syntax, and wire encoding. The original DNS record types are specified in RFC 1035.
View Full IANA DNS Record Type Registry →Notable Less-Common Types
Anatomy of a DNS Record
Every DNS record follows the same five-field structure defined in RFC 1035. Understanding the fields makes every record type immediately readable.
- Name — the hostname this record applies to.
@means the zone apex (the domain itself). Relative names are relative to the zone origin. - TTL — Time to Live in seconds. How long resolvers cache this record. Omitted in zone files when inheriting the zone
$TTLdefault. - Class — almost always
IN(Internet). Historically there were others; ignore them in practice. - Type — the record type: A, MX, TXT, etc.
- RDATA — the record-specific data. Format varies by type.