Query TXT/SPF, DKIM and DMARC at once

Pull SPF, DMARC and DKIM TXT records in one loop for mail audits

for r in example.com _dmarc.example.com sel._domainkey.example.com; do dig +short TXT $r; done

More dig commands

Check CAA records before issuing certs

dig +short CAA example.com

Show which CAs may issue certs; missing CAA lets any CA issue
Resolve SRV records for service discovery

dig +short SRV _sip._tcp.example.com

Get priority/weight/port/target for a service; used by AD, SIP, XMPP
Force TCP and show remaining TTL

dig +tcp +ttlunits +noall +answer example.com @8.8.8.8

Test TCP/53 reachability; +ttlunits prints TTL as 1h/30m not raw seconds
Clean answer-only output

dig +noall +answer example.com

Strip headers/stats; show only the answer section for scripting/diffs
Find authoritative nameservers via NS chase

dig +nssearch example.com

Query each authoritative NS directly; reveals SOA serial mismatches between them