DNS Lookup Explained

What DNS is

The Domain Name System maps names like example.com to addresses and services. Without it you would type IP addresses everywhere. Look up records with the free DNS lookup tool.

The main record types

How a lookup happens

1. You request example.com.
2. The resolver checks its cache.
3. If missing, it asks a root server, then the TLD (.com), then the domain's authoritative name server.
4. The authoritative server returns the record.
5. The resolver caches it for the TTL and answers you.

TTL and propagation

TTL (time to live) says how long resolvers may cache a record. A low TTL (e.g. 300s) speeds up changes; a higher TTL reduces lookup load. "DNS propagation" is really caches expiring.

Common tasks

• Verify a domain — add a TXT record.
• Point a subdomain — A/AAAA or CNAME.
• Set up email — MX plus SPF/DKIM/DMARC TXT records.
• Troubleshoot — compare records from multiple resolvers.

Check a domain's records with DNS lookup and its registration with WHOIS.

A/AAAA vs CNAME

• Use A/AAAA for the root domain.
• Use CNAME for subdomains pointing to a hostname (e.g. a CDN).
• Never point a CNAME at the root where the standard forbids it — use provider-specific ALIAS/ANAME.

Troubleshooting checklist

1. Are the NS records correct?
2. Does the record exist at the authoritative server?
3. Is the TTL still caching an old value?
4. Are A/AAAA pointing at the right IP?
5. Is the service actually listening on the port? (check with port checker)

Look it up

Query any domain's records instantly with the free DNS lookup — no signup, results in your browser.