DNS
Records, DNSSEC, dig/host debugging, authoritative DNS with example-dns.
DNS Records Overview — The Definitive Beginner Guide
Complete reference to all fundamental DNS record types (A, AAAA, CNAME, MX, TXT, NS, SOA, SRV, CAA, PTR), zone syntax, and inspection commands.
DNS A and AAAA Records — Pointing Domains at IP Addresses
Complete beginner guide to IPv4 A records and IPv6 AAAA records, dual-stack configurations, TTL tuning strategies, and CLI verification with dig.
CNAME Aliases — When and How to Use Canonical Name Records
Complete beginner guide to CNAME DNS records, resolution mechanics, why CNAME breaks the zone apex, ALIAS flattening, and the trailing dot rule.
MX Records and Email Deliverability — The SPF, DKIM, and DMARC Trinity
Complete beginner guide to routing incoming email with MX records and achieving 100% inbox delivery using SPF, DKIM, and DMARC authentication.
TXT Records — SPF, DKIM, and DMARC Syntax Masterclass
Complete beginner guide to writing, parsing, and debugging SPF, DKIM, and DMARC TXT records, understanding qualifiers, tags, and avoiding the 10-lookup limit.
DNSSEC Basics — Cryptographic Chain of Trust Explained
Complete beginner guide to DNSSEC, preventing DNS spoofing and cache poisoning, understanding DS, DNSKEY, and RRSIG records, and verifying with dig.
Debugging DNS with dig, host, and nslookup — Complete Sysadmin Toolkit
Master DNS troubleshooting with dig, host, and nslookup, trace root-to-leaf resolution, understand RCODE errors (NXDOMAIN, SERVFAIL), and diagnose cache delays.
Self-Hosting Authoritative DNS with example-dns
Complete beginner guide to running authoritative nameservers, Primary-Secondary replication, AXFR zone transfers, TSIG security, and the example-dns architecture.