https://hanyouqing.com/series/devops-technical-guides/ Recent content in DevOps Technical Guides on Youqing Han - DevOps Engineer Hugo en-us ihanyouqing#gmail.com (#->@) (Youqing Han) ihanyouqing#gmail.com (#->@) (Youqing Han) Mon, 15 Sep 2025 10:00:00 +0800 https://hanyouqing.com/blog/2025/09/comprehensive-dns-guide/ Mon, 15 Sep 2025 10:00:00 +0800ihanyouqing#gmail.com (#->@) (Youqing Han) https://hanyouqing.com/blog/2025/09/comprehensive-dns-guide/ <h1 id="comprehensive-dns-guide">Comprehensive DNS Guide</h1> <p>DNS (Domain Name System) is one of the most fundamental technologies in modern internet infrastructure. As a DevOps or SRE engineer, understanding DNS is crucial for troubleshooting, performance optimization, and system reliability. This comprehensive guide covers all DNS concepts you need to know for real-world scenarios and technical implementations.</p> <h2 id="table-of-contents">Table of Contents</h2> <ol> <li><a href="#dns-fundamentals">DNS Fundamentals</a></li> <li><a href="#dns-record-types">DNS Record Types</a></li> <li><a href="#dns-resolution-process">DNS Resolution Process</a></li> <li><a href="#dns-caching-mechanisms">DNS Caching Mechanisms</a></li> <li><a href="#dns-security">DNS Security</a></li> <li><a href="#performance-optimization">Performance Optimization</a></li> <li><a href="#troubleshooting-dns-issues">Troubleshooting DNS Issues</a></li> <li><a href="#cloud-dns-services">Cloud DNS Services</a></li> <li><a href="#monitoring-and-alerting">Monitoring and Alerting</a></li> <li><a href="#common-dns-scenarios-and-solutions">Common DNS Scenarios and Solutions</a></li> </ol> <h2 id="dns-fundamentals">DNS Fundamentals</h2> <h3 id="what-is-dns">What is DNS?</h3> <p>DNS is a hierarchical, distributed naming system that translates human-readable domain names (like hanyouqing.com) into IP addresses (like 104.21.25.158) that computers use to identify each other on the network.</p>