Articles & Guides
Useful resources for web developers and system administrators
Found 38 · DNS · Reset
DNS
NS DNS Record: What It Is and How to Check It
What an NS DNS record is and how zone delegation works: primary and secondary servers, glue records, checking NS with dig and WHOIS, changing NS servers and common mistakes.
DNS
CAA DNS Record: Control Which CAs Issue Your SSL
What a CAA DNS record is, why it matters, the issue/issuewild/iodef syntax, and how to check it. Stop unauthorized SSL certificate issuance for your domain.
DNS
SPF Too Many DNS Lookups (10-Lookup Limit) Fix
SPF too many DNS lookups error: what the 10-lookup limit means and how to fix it. Counting include, mx, a, SPF flattening, macros and checking with dig.
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
DNS_PROBE_FINISHED_NXDOMAIN means a domain will not resolve. Step-by-step diagnosis, dig and nslookup commands, plus DNS cache flush on Windows, macOS, Linux.
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.