Real-world guides written by SREs and DNS operators. No "DNS is like a phonebook" analogies. Just clear explanations, RFCs cited, and copy-pasteable examples.
The foundational DNS record type that maps a hostname to an IPv4 address.
IPv6 addressing for DNS — when, why, and how to publish them.
Why you can't CNAME the apex of a zone — and what to do instead.
How priority works, what 0 means, and why having backup MX is a 1995 idea.
Three protocols, one goal: making sure your emails actually arrive.
Force TLS on incoming mail — the modern way to protect SMTP.
Trust chains, NSEC vs NSEC3, key rollover ceremonies, and what can go wrong.
Stop unauthorized CAs from issuing certs for your domain.
Dangling CNAMEs are how attackers steal your subdomain. Here's how to find them.
How TTL affects cache hits, failover speed, and your DNS bill.
Why every serious DNS provider uses anycast — and what it actually does.
A field guide to DNS command-line tools, with practical examples.
Points a hostname to an IPv4 address. The most common record on the internet.
The IPv6 equivalent of an A record. 128-bit addresses.
Alias one hostname to another. Cannot coexist with most other records.
Directs email delivery to mail servers, ordered by priority.
Arbitrary text. Used for SPF, DKIM, DMARC and domain verification.
Delegates a zone to the authoritative DNS servers for it.
Administrative info about the zone — primary NS, contact, serial, timers.
Restricts which CAs can issue SSL certificates for the domain.
Reverse mapping — IP address back to a hostname.
Locates services on the network, used by VoIP, XMPP, Minecraft and more.
Holds the hash of a DNSKEY in the parent zone, part of DNSSEC trust chain.
Public keys used to verify DNSSEC signatures on records.