Articles & Guides
Useful resources for web developers and system administrators
Found 44 · DNS · Reset
DNS
SPF Record Explained: Syntax and -all
SPF record explained: v=spf1 syntax, include, a, mx, ip4 mechanisms and the ~all vs -all difference. Example records, dig commands and common SPF mistakes.
DNS
DNS_PROBE_FINISHED_NXDOMAIN: Fix It in Chrome, Mac and Android
DNS_PROBE_FINISHED_NXDOMAIN means the name did not resolve. Fix it in Chrome, Edge, Mac and Android: cache flush, secure DNS, dig checks and owner-side fixes.
DNS
ERR_NAME_NOT_RESOLVED Fix
ERR_NAME_NOT_RESOLVED means the browser couldn't turn the domain into an IP. Learn the DNS causes, diagnose with nslookup and dig, and fix it step by step.
DNS
DNS Monitoring: Why and How
DNS monitoring guards against silent failures: record tampering, expired resolution, failover issues. How to set up a DNS monitor and check records with dig.
DNS
Best DNS Lookup Tools 2026
The best DNS lookup tools of 2026 compared: DNSChecker, WhatsMyDNS, enterno.io, dig and more. Check records, propagation, diagnostics and monitoring.
DNS
Wildcard DNS Records: Use Cases and Pitfalls
Wildcard DNS (*.example.com): use cases, RFC 4592 constraints, conflicts, performance, and security implications.
DNS
Reverse DNS and PTR Records: Why You Need Them
What rDNS and PTR records are. Setting up in-addr.arpa reverse zones, PTR for mail servers, and the impact on SPF and email deliverability.
DNS
DNS Leak: What It Is, How to Test and Fix
DNS leak on VPN — what it is, why it matters, and how to fix it. Step-by-step tests and fixes for Windows, macOS, Linux, iOS, Android.
DNS
What Is a DNS Server: Types, How to Find Yours and Fix It
What a DNS server is: how recursive, authoritative, root and TLD servers differ, how to find the one you use, change it, and fix it when it stops responding.
DNS
MX Records for Email: Step-by-Step Setup Guide
Full MX records setup for Google Workspace, Yandex 360, Zoho. Priority, RFC 5321, SPF/DKIM/DMARC, and delivery testing.