Network & IP Reference

DNS Record Types Reference Chart

Quick reference for DNS record types, TTL guidance, format examples, and common planning mistakes. Use this page for fast orientation, then use the checker to query live records.

Use DNS checker Back to charts

Terms

DNSDomain Name System: The internet's phone book — it translates human-readable website names (like example.com) into the numeric addresses computers actually use to find each other.

DNS record types quick reference

Each record type has a specific purpose. Using the wrong type is a common source of mail delivery failures, certificate issuance errors, and broken services.

Type	Purpose	Typical TTL	Value format	Notes
A	Maps a hostname to an IPv4 address	300 – 3 600 s	`192.0.2.1`	Most common record. Use low TTL if the IP may change.
AAAA	Maps a hostname to an IPv6 address	300 – 3 600 s	`2001:db8::1`	Required for dual-stack deployments.
MX	Mail server for the domain	3 600 – 86 400 s	`10 mail.example.com.`	Priority value (lower = preferred). Needs matching A/AAAA.
TXT	Free-text data — SPF, DKIM, DMARC, domain verification	300 – 3 600 s	`"v=spf1 include:… ~all"`	Multiple TXT records allowed. SPF must be only one.
CNAME	Alias — points hostname to another hostname	300 – 3 600 s	`target.example.com.`	Cannot be used at the zone apex (root domain).
NS	Authoritative nameservers for the zone	86 400 s	`ns1.example.com.`	Changed at the registrar. Propagation can take up to 48 h.
SOA	Zone metadata — serial, refresh, retry, expire, minimum TTL	86 400 s	`ns1.example.com. admin.example.com. …`	One SOA per zone. Serial must increment on every zone change.
SRV	Service location — protocol, port, priority, weight	300 – 3 600 s	`10 20 443 target.example.com.`	Used by SIP, XMPP, Minecraft, and others.
PTR	Reverse lookup — IP address to hostname	3 600 s	`host.example.com.`	Managed by the IP block owner, not the domain registrar.
CAA	Specifies which CAs may issue TLS certificates for the domain	3 600 s	`0 issue "letsencrypt.org"`	Checked by CAs before issuance. Recommended for all domains.

TTL planning guidance

TTL (Time To Live) controls how long resolvers cache a record. Set it before you need it — lowering TTL only helps after old caches have already expired.

TTL value	Label	When to use
60 s	Emergency / migration	Pre-migration or DNS failover. Set at least 24 h before the cut.
300 s	Dynamic / cloud	Cloud IPs, CDN origins, services that may change frequently.
3 600 s	Normal	Standard web services with occasional planned changes.
86 400 s	Stable	MX, NS, SOA, and rarely-changing infrastructure records.

Migration rule:Lower TTL to 60 s at least 24 hours before the planned change. After the change is confirmed stable, raise TTL back to a normal value.

How to use this chart

Identify the record type that matches your question (routing, mail, alias, verification).
Enter the domain in the checker and select the correct record type.
Check the TTL — it tells you how long cached answers will persist.
For SPF/DKIM/DMARC validation, look inside TXT record values.
For propagation issues, check the NS records first to confirm the right nameservers are responding.
If CNAME is present at a subdomain, do not also expect A records on that same name.

SPF = one TXT record · DKIM = TXT at selector._domainkey · DMARC = TXT at _dmarc

Common mistakes

Setting CNAME at the zone apex (e.g. example.com itself) — DNS forbids this.
Leaving TTL at 86 400 s before a planned IP migration.
Adding multiple SPF TXT records instead of combining them into one.
Expecting instant propagation — resolvers cache until TTL expires.
Forgetting that MX records must resolve to an A or AAAA, not a CNAME.
Checking DNS before the TTL of the old record has expired.

CNAME at apex — why it fails

A CNAME at the zone apex (e.g. example.com) conflicts with required SOA and NS records. DNS does not allow other record types alongside a CNAME on the same name.

Use A/AAAA at the apex directly, or use your DNS provider's ALIAS / ANAME / CNAME-flattening feature if available. These are provider-specific extensions, not standard DNS.

Propagation and caching

DNS changes do not apply instantly. Old records are cached by resolvers worldwide until the TTL expires.

Low TTL (60 s) means most resolvers pick up changes quickly.
High TTL (86 400 s) means stale answers persist for up to 24 hours.
NS record changes at the registrar can take 24 – 48 hours globally.
Some ISP resolvers ignore TTL and cache longer than specified.

FAQ

What is the difference between SPF, DKIM, and DMARC?

SPF (TXT at root) declares which servers may send mail. DKIM (TXT at selector._domainkey) cryptographically signs outgoing mail. DMARC (TXT at _dmarc) tells receivers what to do when SPF or DKIM fails, and where to send reports.

Why does the DNS checker use Cloudflare DoH?

The checker queries Cloudflare's DNS over HTTPS (DoH) endpoint directly from your browser. No server-side proxy is needed, and queries stay within your browser session. Results reflect what Cloudflare's resolvers see, which may differ slightly from your local ISP resolver.

Can I use this chart to debug mail delivery failures?

Yes. Check MX records first (do they resolve?), then TXT records for SPF and DKIM selectors, then TXT at _dmarc. Most mail failures trace back to missing or misconfigured records in those three areas.

What does a trailing dot mean in DNS values?

A trailing dot (e.g. mail.example.com.) indicates a fully qualified domain name (FQDN). Without the dot, some DNS software appends the origin zone. In raw zone files, always use FQDN with trailing dot. Most DNS GUIs handle this automatically.

Next step

Need to check live records?

Use the DNS Record Checker to query A, AAAA, MX, TXT, CNAME, NS, and SOA records in real time using Cloudflare DNS over HTTPS.

Open DNS checker →

Disclaimer

This reference chart provides planning guidance only. DNS behaviour depends on your specific provider, registrar configuration, resolver behaviour, and propagation state. Always verify live record values directly against your authoritative nameservers before relying on cached results.