Resources

Guides, tutorials, and reference articles for DNS monitoring and management.

Guides

The Complete DNS Guide for Website Owners

Everything website owners need to know about DNS: how it works, record types, propagation, troubleshooting, security, and monitoring.

DNS Security and Monitoring Guide

A complete guide to DNS security: threats, DNSSEC, hijacking detection, change management, multi-provider strategies, and incident response.

Knowledge Base

DNS AAAA Record Explained: IPv6 Addresses

What DNS AAAA records are, how they differ from A records, when you need them, how to create and verify AAAA records, and how dual-stack DNS works.

How to Check DNS Propagation After Making Changes

Learn how to check DNS propagation status after making changes. Understand TTL, use global propagation checkers, and avoid common mistakes.

How to Check and Verify MX Records

Learn how to check and verify MX records for any domain. Covers dig, nslookup, web tools, priority values, and common email provider configurations.

How to Check TXT Records: SPF, DKIM, and DMARC

Learn how to check TXT records including SPF, DKIM, and DMARC. Covers lookup methods, validation techniques, and common misconfigurations to avoid.

Common DNS Errors and What They Mean

A complete reference guide for DNS error codes and common problems including NXDOMAIN, SERVFAIL, REFUSED, and browser-level DNS errors with causes and fixes.

dig Command: DNS Lookups from the Command Line

How to use the dig command for DNS lookups: basic syntax, querying record types, +short output, specifying nameservers, +trace for full resolution, batch queries, and dig vs nslookup.

DNS CAA Record: Controlling Certificate Issuance

What DNS CAA records are, how they control which certificate authorities can issue SSL certificates for your domain, and how to set them up correctly.

DNS Caching and TTL: What They Mean for Your Site

Understand how DNS caching works at every level, what TTL values mean, how to choose the right TTL, and best practices for faster propagation.

DNS Change Management: A Strategy for Zero-Downtime Updates

A strategic framework for managing DNS changes with zero downtime. Covers pre-change checklists, TTL management, staged rollouts, and rollback plans.

What Is DNS Failover? How It Keeps Sites Online

How DNS failover works, how health checks trigger automatic record updates, TTL considerations, provider options, and when to use DNS-based failover vs alternatives.

DNS Hijacking: How It Works and How to Detect It

Learn how DNS hijacking works, the different types of DNS attacks, real-world examples, and how to detect and prevent DNS spoofing and poisoning.

DNS Monitoring Explained: Why Uptime Checks Aren't Enough

Learn what DNS monitoring is, how it differs from uptime monitoring, what it watches, who needs it, and why uptime checks alone miss critical issues.

DNS Monitoring Glossary: Terms You Should Know

A comprehensive A-Z glossary of DNS and monitoring terminology. Over 50 essential terms defined with clear, concise explanations for IT professionals.

DNS over HTTPS (DoH) Explained

What DNS over HTTPS is, how it encrypts DNS queries over HTTPS, how DoH compares to DoT and traditional DNS, and how to enable it in your browser or system.

How to Fix dns_probe_finished_nxdomain

What the dns_probe_finished_nxdomain error means, why it happens, and step-by-step fixes for Chrome, Windows, macOS, and Linux.

DNS Propagation: What It Is and Why It Takes Time

Learn what DNS propagation really is, why it takes time, and how TTL affects how quickly DNS changes appear worldwide. Debunk the 48-hour myth.

How to Audit DNS Records Across Your Domain Portfolio

Learn how to audit DNS records across your domain portfolio. Covers audit checklists, identifying stale records, security gaps, and automating ongoing audits.

DNS Record History: How to Track Changes Over Time

How to track DNS record changes over time, why it matters for security and troubleshooting, and the tools and methods available for historical DNS lookups.

DNS Record Types Explained: A, AAAA, CNAME, MX, TXT, NS, SOA

A complete guide to DNS record types including A, AAAA, CNAME, MX, TXT, NS, and SOA records. Learn when to use each type with real-world examples.

DNS Record Types: Complete Reference Guide

A complete reference guide covering all DNS record types including A, AAAA, CNAME, MX, TXT, NS, SOA, SRV, PTR, CAA, and NAPTR with syntax, usage, and examples.

DNS Replication: How It Works and How to Verify

How DNS replication works between primary and secondary nameservers, zone transfers, AXFR and IXFR protocols, and how to verify that replication is working correctly.

How DNS Resolution Works (Step by Step)

A step-by-step guide to how DNS resolution works, from browser cache to authoritative nameserver. Understand recursive and iterative queries.

DNS Security Best Practices for Your Domain

A comprehensive DNS security checklist covering DNSSEC, registrar locks, CAA records, email authentication, monitoring, and more to protect your domain.

DNS Server Not Responding: How to Fix

What the 'DNS server not responding' error means, why it happens, and step-by-step fixes for Windows, macOS, and Linux. Covers router issues, resolver problems, and network misconfigurations.

How to Test Your DNS Speed

How to test DNS query speed, what affects DNS performance, tools for benchmarking DNS resolvers and authoritative servers, and how to improve DNS response times.

DNS Troubleshooting: How to Fix Common DNS Problems

Systematic guide to troubleshooting DNS problems. Covers site not loading, email failures, propagation delays, NXDOMAIN, SERVFAIL, and wrong IP resolution.

DNS TTL Explained: How to Choose the Right Value

What DNS TTL is, how caching works at each level, common TTL values for different situations, and how to choose the right TTL for your records.

What Is a DNS Zone?

What DNS zones are, how they differ from domains, the structure of a zone file, zone delegation, and how zones enable the distributed nature of DNS.

How to Flush DNS Cache on Every Platform

Step-by-step instructions to flush DNS cache on Windows, macOS, Linux, Chrome, Firefox, Safari, and routers. Learn when and why to clear your DNS cache.

How to Change Nameservers Without Breaking Your Site

Step-by-step guide to safely changing nameservers. Covers pre-migration checklist, TTL management, record verification, monitoring, and rollback strategy.

How to Check DNS Records for Any Domain

Learn how to check DNS records using command-line tools, web-based lookups, and monitoring platforms. Covers dig, nslookup, and online DNS checkers.

How to Fix Slow DNS Lookups

Diagnose and fix slow DNS lookups. Covers common causes like ISP resolvers, high TTLs, and provider issues, plus step-by-step fixes using dig, nslookup, and browser DevTools.

How to Monitor DNS Records for Unexpected Changes

Learn how to monitor DNS records for unauthorized or unexpected changes. Covers manual approaches, automated monitoring, alerting, and incident response.

Why You Should Use Multiple DNS Providers

Learn why DNS redundancy matters and how to implement a multi-provider DNS strategy with primary/secondary or active/active configurations for maximum uptime.

DNS NS Record Explained

What DNS NS records are, how they delegate authority for domains and subdomains, how to check them, and common NS record problems.

nslookup Command: Complete Guide to DNS Queries

How to use the nslookup command for DNS queries: basic syntax, querying record types, specifying DNS servers, interactive mode, troubleshooting, and nslookup vs dig.

DNS PTR Record: Reverse Lookups Explained

What DNS PTR records are, how reverse DNS lookups work, why they matter for email deliverability, and how to set up and verify PTR records.

Public DNS Providers Compared: Google, Cloudflare, Quad9, and More

Compare the best public DNS providers including Google, Cloudflare, Quad9, OpenDNS, and NextDNS. Covers speed, privacy, security features, and IP addresses.

How to Perform a Reverse DNS Lookup

Learn how to perform reverse DNS lookups to find the domain associated with an IP address. Covers PTR records, dig -x, nslookup, and email deliverability.

DNS SOA Record Explained

What SOA records contain, how to read each field, why they matter for zone transfers and secondary DNS, and how to check and configure SOA records.

SPF, DKIM, and DMARC: DNS Records for Email Authentication

How SPF, DKIM, and DMARC DNS records work together to authenticate email, prevent spoofing, and protect your domain. Includes record syntax, setup steps, and common mistakes.

DNS SRV Record Explained

What DNS SRV records are, how they work, their syntax and fields, and how services like VOIP, XMPP, and Microsoft 365 use them for service discovery.

What Are Nameservers? A Practical Guide

Nameservers are the backbone of DNS. This guide explains what nameservers do, how they work, why your registrar asks you to set them, and how to check and change them.

What Happens When DNS Records Change Unexpectedly

Understand the impact of unexpected DNS record changes, how unauthorized modifications happen, and how to detect and respond to DNS incidents.

What Is a CNAME Record? When to Use One

What a DNS CNAME record is, how alias resolution works, when to use CNAMEs for CDNs and SaaS services, restrictions at the zone apex, and CNAME vs A record differences.

What Is a DNS Server? How DNS Servers Work

What DNS servers are, how they work, the four types involved in DNS resolution (recursive, root, TLD, authoritative), public DNS options, and how to find or change your DNS server.

What Is a Subdomain? How Subdomains Work

What subdomains are, how they work in DNS, common uses, how to create them, and the SEO and technical implications of using subdomains vs subdirectories.

What Is DNSSEC? How It Protects Your Domain

What DNSSEC is, how the chain of trust works from root to domain, how DNS responses are validated with RRSIG and DNSKEY records, and how to enable DNSSEC on your domain.

Why DNS Records Matter More Than You Think

DNS records are the invisible routing layer behind every website, email, and online service. Learn why getting them right is critical for uptime and security.

Wildcard DNS Records: How They Work

How wildcard DNS records work, which record types support them, practical use cases, security risks, and when you should avoid using wildcards.