DNS Issues
DNS Record Not Found
A "DNS record not found" error (NXDOMAIN) means the queried domain or record type does not exist in DNS. This can occur for legitimately non-existent domains, but also indicates missing records that should be present—such as deleted A records, unpublished MX records, or misconfigured subdomains.
Symptoms
- Browser shows "This site can't be reached" or "DNS_PROBE_FINISHED_NXDOMAIN"
- dig or nslookup returns NXDOMAIN status
- Email bounces with "host not found" errors
- Subdomain accessible yesterday now returns NXDOMAIN
Common Causes
- DNS record was accidentally deleted
- Domain registration expired and was removed from the zone
- Subdomain never had a DNS record created
- Nameserver delegation is broken or points to wrong servers
- Typo in domain name in client configuration
Step-by-Step Troubleshooting
- 1
Verify the domain name
Ensure the queried domain name is spelled correctly and hasn't expired.
Use WHOIS Lookup → - 2
- 3
Check nameserver delegation
Verify the nameservers are correctly configured at the registrar.
Use NS Record Lookup → - 4
Check specific record types
Query for the specific record type (A, MX, CNAME) that is expected.
Use DNS Lookup → - 5
Re-create the missing record
If the record was deleted, re-create it at your DNS provider with the correct values.
Recommended Diagnostic Tools
Monitor DNS Availability
Get alerts if DNS records disappear or domains become unresolvable.