DNS Fundamentals
Common DNS record types and their purposes.
The DNS record types that appear in everyday zone files: address records, aliases, mail routing, delegation, text records and zone authority, plus the reverse-lookup, service-location, certificate-authority and DNSSEC types operators meet next. Each row says what the record maps and what it is used for.
Use it when
- You are configuring or debugging DNS for a domain, mail setup or certificate issuance.
- You need to know which record type answers a given question.
Watch out for
- Answers depend on the record type queried; a name can have several types at once.
- A CNAME cannot coexist with other record types at the same name, which is why the zone apex needs special handling.
The data
16 rows
| Type | Description |
|---|---|
| A | Maps a hostname to an IPv4 address. |
| AAAA | Maps a hostname to an IPv6 address. |
| CNAME | Canonical name alias for another domain. |
| MX | Mail exchange record for email routing. |
| NS | Authoritative name server for the domain. |
| TXT | Arbitrary text often used for verification and SPF. |
| SOA | Start of authority record with zone metadata. |
| PTR | Maps an IP address back to a hostname, used for reverse DNS. |
| SRV | Locates a service by naming its host and port, with priority and weight. |
| CAA | Lists the certificate authorities permitted to issue certificates for the domain. |
| DNSKEY | Holds a public key used to verify DNSSEC signatures for the zone. |
| DS | Delegation Signer: a hash of a child zone's key placed in the parent to chain DNSSEC trust. |
| RRSIG | A DNSSEC signature over a set of records. |
| HTTPS | Service binding for HTTPS: advertises alternative endpoints and supported protocols such as HTTP/3 (SVCB family). |
| NAPTR | Name Authority Pointer: rewrite rules used in telephony number mapping and some service discovery. |
| TLSA | Associates a TLS certificate or key with a service name, used by DANE. |
Fields
The shape of this dataset, read from the data itself: every column, its type and a real value. Agents can use this to plan a query without fetching the whole document.
| Section | Field | Type | Example |
|---|---|---|---|
| data | type | string | A |
| data | description | string | Maps a hostname to an IPv4 address. |
Fetch the same bytes
The static files contain the same reference rows as the API, with no API rate limit. Live metadata, such as view counts, may differ. Use the API for content negotiation; use the static files for a cacheable snapshot.
curl "https://yjtoon.com/api/dataset/dns-fundamentals?format=toon"
const res = await fetch( "https://yjtoon.com/static-data/dataset/dns-fundamentals.toon" ); const toon = await res.text();
Rate limit: 120 requests per minute per IP, no key and no signup. API reference →