Good DNS troubleshooting usually starts with a small set of repeatable queries. The examples below cover the checks most administrators use during migrations, email setup, SSL validation, and website outages.
Website address records
dig example.com A
dig example.com AAAAUse these first when a website does not resolve or points to the wrong hosting provider.
Email routing records
dig example.com MX
dig example.com TXT
dig _dmarc.example.com TXTMX shows where mail should be delivered. TXT often contains SPF and domain verification records. DMARC usually lives at _dmarc.example.com.
Delegation and authority
dig example.com NS
dig example.com SOA
dig +trace example.comUse these when records look right in a DNS dashboard but the public internet is still seeing old or missing data.
Reverse DNS
dig -x 203.0.113.10Reverse DNS is common for mail servers, security logs, and network inventory. It maps an IP address back to a hostname using PTR records.
DNSSEC checks
dig example.com DS
dig example.com DNSKEY
dig example.com A +dnssecDNSSEC records help validate that DNS answers have not been altered. Use DS and DNSKEY checks when enabling DNSSEC or investigating validation failures.