What is DNS?
A clear explanation of the Domain Name System and why every site depends on it.
How DNS Works
Follow a lookup from stub resolver to root, TLD and authoritative nameserver.
DNS Record Types
A field guide to A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, SRV and PTR.
DNS Propagation Explained
Why changes take time, how TTL really works, and how to check worldwide.
How to Check DNS Records
A practical walkthrough using DNSFetch, dig, nslookup and public resolvers.
MX Records Explained
How mail routing works, priority values, and what to publish for Google or Microsoft.
SPF Explained
Mechanisms, the 10-lookup limit, and how to write a policy that does not break mail.
DMARC Explained
Alignment, policies, reports, and a safe rollout from p=none to p=reject.
DKIM Explained
Selectors, public keys, and how DKIM signatures prove a message was not altered.
CNAME vs A Record
When to alias, when to point at an IP, and why the apex cannot be a CNAME.
DNS TTL Explained
How long resolvers cache answers and how to plan a painless migration.
Nameservers Explained
Registrar vs DNS host, glue records, and what NS records actually control.
IPv4 vs IPv6 DNS
A and AAAA records, dual-stack sites, and Happy Eyeballs in the real world.
Email Authentication
SPF, DKIM and DMARC together — the stack that stops domain spoofing.
What is DNSSEC?
How signed zones stop cache poisoning, plus DS, DNSKEY, RRSIG and DS at the parent.
Common DNS Errors
NXDOMAIN, SERVFAIL, missing records, split-brain and how to diagnose each one.
How to Change DNS Records
A checklist for editing records without taking a site or inbox offline.
DNS Caching Explained
Browser, OS, resolver and CDN caches — and how to flush the one that is lying.
DNS FAQ
Straight answers to the questions people ask when a domain or mailbox misbehaves.