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The DNSDecode Blog
Practical, plain-English guides to DNS, email authentication, and domain troubleshooting.
🔮 DNS fact: The .com TLD was one of the original six top-level domains created in 1985 — the very first .com ever registered was symbolics.com, for a defunct computer company.
How to Check if DNS Has Propagated (And Why It Takes So Long)
What DNS propagation actually means, why it can take anywhere from minutes to 48 hours, and how to check it properly across multiple resolvers.
SPF, DKIM, and DMARC Explained: The Complete Guide to Email Authentication
A plain-English breakdown of how SPF, DKIM, and DMARC work together to stop email spoofing, and how to set them up correctly.
What Is DNSSEC and Do You Actually Need It?
How DNSSEC protects DNS from spoofing and cache-poisoning attacks, what enabling it actually involves, and when it genuinely matters.
DNS Record Types Explained: A Record, CNAME, MX, TXT, and More
A practical reference for every common DNS record type — what each one does, when to use it, and what a healthy configuration looks like.
How to Diagnose DNS Resolution Issues (A Step-by-Step Approach)
A practical troubleshooting flow for "this domain won't resolve" problems — from checking the basics to tracking down authoritative nameserver failures.
DNSDecode vs MXToolbox: Which Should You Use?
An honest comparison of DNSDecode and MXToolbox — what each tool is built for, where they overlap, and when to reach for one over the other.
dig, nslookup, and DNSDecode: When to Use Each DNS Tool
Command-line DNS tools and web-based analysis platforms solve different problems. Here is when each one is actually the right choice.
DNS Migration Checklist: Moving Providers Without Downtime
A step-by-step checklist for migrating DNS to a new provider — or moving a domain to new hosting — without breaking email or causing an outage.
Reverse DNS (PTR) Records: What They Are and Why Mail Servers Care
How PTR records work, why they matter disproportionately for email deliverability, and how to check and fix yours.
5 Famous DNS Outages That Broke the Internet (And What They Taught Us)
From a single mistyped router command to a botnet made of hacked security cameras, here are the DNS failures that took down half the web and the lessons each one left behind.
7 DNS Myths That Refuse to Die
DNS is one of the most misunderstood parts of the internet. Here are seven persistent myths, and the less exciting truth behind each one.
The Weirdest DNS Record Types You Have Probably Never Used
Beyond A, MX, and TXT lies a strange little zoo of DNS record types built for geolocation, SSH verification, and problems most of us have never had to solve.
How DNS Becomes a Weapon (And How Operators Shut the Door)
DNS amplification attacks turn small queries into massive floods of traffic aimed at a victim. Here is how the mechanism works conceptually, and the defensive controls that stop a server from being abused as part of one.
The DNS Glossary: Every Term Decoded, Zero Boring Textbook Vibes
Resolver, zone, glue record, anycast, negative caching — a fast, plain-English glossary of the DNS terms you keep half-understanding.
Why Does Your Website Feel Slow? DNS Might Be the Silent Culprit
Before a browser can even request your homepage, it has to finish a chain of DNS lookups. Here is how much that chain actually costs you, and how to shorten it.