DNS issues can be confusing since symptoms often appear elsewhere (a "site not found" error doesn't obviously point to DNS). This guide covers the most common DNS errors and their fixes.
NXDOMAIN (Domain Doesn't Exist)
The queried domain has no DNS records at all, or doesn't exist in the queried zone — verify the domain is spelled correctly, and check that DNS records actually exist for it:
dig yourdomain.comSERVFAIL
The DNS server encountered an error trying to process the query — often indicates a misconfiguration on the authoritative nameserver, or a DNSSEC validation failure. Check the nameserver's own logs, and verify DNSSEC configuration if enabled (see How to Set Up DNSSEC for Your Domain).
Domain Resolves to the Wrong IP
Check for a stale cached record (see Understanding DNS Propagation and TTL) versus a genuine misconfiguration — verify the current record directly at the authoritative source:
dig @your-nameserver.com yourdomain.com"Too Many Redirects" Combined with DNS Confusion
Sometimes appears DNS-related but is actually an HTTP redirect loop — check your web server/CDN redirect configuration rather than DNS records themselves if this specific error appears.
MX Record Issues Causing Email Delivery Failures
dig yourdomain.com MXVerify MX records point to the correct mail server hostname, and that hostname itself resolves correctly — see How to Configure MX Records for Email Delivery for the full setup guide.
CNAME Conflicts
A CNAME record cannot coexist with other record types (like MX or TXT) at the same name — this is a common configuration error; see How to Use CNAME Records Correctly for the specific rules.
DNS Not Updating Despite Correct Configuration
Almost always a TTL/caching issue — see Understanding DNS Propagation and TTL; verify the record is actually correct at the authoritative source, then wait out the TTL, or query specific resolvers directly to check current state.
Nameserver Delegation Issues
dig yourdomain.com NSVerify the nameservers shown match what's actually configured at your domain registrar — a mismatch here (registrar pointing to different nameservers than expected) is a common source of confusing, hard-to-diagnose DNS issues.
DNS Working for Some Users but Not Others
Often a propagation timing difference (see Understanding DNS Propagation and TTL) or, less commonly, an issue specific to certain resolvers — test explicitly against multiple public resolvers (dig @8.8.8.8, dig @1.1.1.1) to isolate whether it's genuinely resolver-specific.
A Systematic DNS Troubleshooting Approach
- Query the authoritative nameserver directly first, ruling out propagation delay
- Verify the record type and value are exactly correct
- Check for conflicting record types at the same name
- Verify nameserver delegation is correctly configured at the registrar
Continue Reading
- How to Use dig and nslookup for DNS Troubleshooting
- Understanding DNS Propagation and TTL
- DNS Fundamentals: A, AAAA, CNAME, MX, TXT & NS Records Explained
Browse more articles in Networking & DNS.
