DNS Lookup FAQs

Answers to common questions about using AuthLookup.com to check public DNS records through recursive resolvers and authoritative nameservers.

What does AuthLookup.com do?

AuthLookup.com checks public DNS records for a domain or host. It can query Cloudflare DNS, Google DNS, the server's local resolver, or the domain's authoritative nameservers and then show the answers returned.

Which resolver should I choose?

Use Cloudflare or Google to see what major public recursive resolvers return. Use Authoritative to ask the domain's delegated nameservers directly. Use Local to see the resolver path available to the AuthLookup.com server.

What is an authoritative nameserver?

An authoritative nameserver is delegated to answer for a DNS zone. It is usually the best place to confirm whether the source-of-truth DNS records have been updated, although recursive resolvers may still cache older answers until their TTL expires.

Why do Cloudflare, Google, and authoritative results differ?

Results can differ because of caching, TTLs, recent DNS changes, DNSSEC validation, resolver policy, or temporary nameserver availability. Comparing resolvers can help show whether a change has reached authoritative DNS and whether recursive caches have refreshed.

Which DNS record type should I check?

Use A or AAAA for website IP addresses, CNAME for aliases, MX for mail routing, TXT for SPF or verification records, NS for delegation, SOA for zone metadata, CAA for certificate authority policy, and DS or DNSKEY for DNSSEC. See DNS Terminology for a fuller record-type guide.

What does TTL mean?

TTL means time to live. It is the number of seconds a DNS answer may be cached by resolvers before they should refresh it. A lower TTL can make changes appear faster, while a higher TTL can keep older answers cached longer.

What does NXDOMAIN mean?

NXDOMAIN means the queried DNS name does not exist according to the resolver or nameserver that answered. Check spelling, the exact hostname, and whether the record has been created in the correct DNS zone.

What does SERVFAIL mean?

SERVFAIL means the resolver or nameserver could not complete the lookup. Common causes include DNSSEC problems, unavailable authoritative nameservers, delegation issues, or temporary resolver failures.

Can AuthLookup.com check DNS propagation?

AuthLookup.com can compare selected resolver views, which is useful for propagation checks. For broader multi-location DNS consistency testing, use DNSproblem.com.

Can AuthLookup.com diagnose SPF, DKIM, or DMARC issues?

AuthLookup.com can show the underlying TXT, CNAME, MX, and related records, but it does not fully evaluate email authentication policy. For dedicated SPF, DKIM, and DMARC diagnostics, use AuthProblem.com.

Does AuthLookup.com store the domains I query?

AuthLookup.com keeps aggregate usage statistics and short-term access logs for reliability and abuse prevention. Aggregate counters do not include queried domain names, and access logs do not include DNS lookup request bodies. See the Privacy page for more detail.

Can I use AuthLookup.com from bots or automated systems?

AuthLookup.com is intended for interactive, human-led diagnostics. Automated, high-volume, scraping, monitoring, or load-testing use is not permitted without specific written permission. Please contact us first if you need approved automated access.