Troubleshooting Articles
Diagnose and fix common DNS problems that cause downtime and email failures.
5 min read
What Is SERVFAIL? Understanding DNS Server Failure Responses
SERVFAIL is the DNS response code that means a resolver encountered an error during lookup — the domain might exist, but the server could not determine the answer. Learn what causes SERVFAIL, how to diagnose it, and how to fix it.
7 min read
What Is NXDOMAIN? Understanding the 'Domain Does Not Exist' DNS Response
NXDOMAIN is the DNS response code that means a domain name does not exist. Learn what triggers it, how to troubleshoot it, the difference between NXDOMAIN and SERVFAIL, and when NXDOMAIN indicates a security issue.
11 min read
DNS Troubleshooting Tools: What the Pros Actually Use
A practical overview of every DNS diagnostic tool worth knowing — from dig and nslookup to packet captures and performance testing — with real examples of when and how to use each one.
12 min read
DNS Propagation Myths Debunked: It's Really About Cache Freshness
The term 'DNS propagation' is everywhere, but it describes something that doesn't actually happen. I debunk the biggest myths and explain what's really going on: cache freshness.
10 min read
Troubleshooting Common DNS Issues: A Step-by-Step Guide
Learn how to diagnose and fix the most common DNS problems, from websites not loading to NXDOMAIN errors, using practical command-line tools and DNS Checker.