DNS records lookup

What the DNS lookup shows

This DNS lookup asks for a domain's seven common record types in one run: A, AAAA, NS, MX, TXT, SOA and CAA. Each query goes straight to Cloudflare's 1.1.1.1 from the IPVIEW server over the toolkit's own DNS engine, UDP first and TCP if the answer was truncated, never through your device's resolver. What you see is the answer as published and cached by a public resolver, not what your office network or ISP has decided to tell you.

A single label such as ir is accepted, because asking about a zone opens no socket. CNAME is not among the seven: an aliased name answers the other types through its target, the CNAME record tool shows the alias published at the name, and the Full report follows the chain. Twenty requests a minute are allowed in total across the DNS, WHOIS, SSL and email tools.

How to read the result

Each type has its own Name, Value and TTL table. The TTL is the number of seconds a resolver may keep the record, so a change you have just made is not visible everywhere until the old TTL has run out. Under 60 seconds makes every visitor pay for a lookup; above a day keeps a mistake alive for a day after you fix it.

An empty section is read from the response code, and the three cases differ. No MX record means the zone answered and that type is not set. The name does not exist at all is NXDOMAIN. The query failed means the resolver got no answer, which is not a fact about the zone: a domain returning SERVFAIL on all seven types looks empty when it is unreachable. From inside Iran, an A record inside 10.0.0.0/8 for a public site is an injected answer; the Reachability check names it.

When it is useful

The first stop when a site or mailbox stops working: see the addresses, mail servers and nameservers together before choosing a single-record tool. If the A record is right and the site still does not load, the fault is past DNS, and Ping or the Reachability check is the next question.

After editing a zone, to see whether the published answer has changed and with what TTL. If it has not, the SOA serial here says whether the zone was actually reloaded, and DNS propagation shows which resolvers still give the old answer.

Common questions

Which resolver does the DNS lookup use?

Cloudflare's 1.1.1.1, asked directly from the IPVIEW server over UDP, then TCP if truncated. Your own device's resolver is never involved, so a stale or rewritten local answer does not reach the page.

Why does a section say the query failed?

The resolver returned SERVFAIL, REFUSED or nothing. That is a failure to ask, not an empty record: the zone may hold the record and its nameservers may not be answering. Delegation check says whether they are reachable.

The record I just changed is still old. Why?

The resolver serves its cached copy until the previous TTL expires; the TTL column shows the seconds left on the copy it holds. DNS propagation puts the same question to six resolvers at once.