It's Always DNS! Understanding DNS in the Cloud and On-Prem

When things go wrong in a networked environment, experienced engineers often yell "It's always DNS!" and they're not entirely wrong. The Domain Name System is the internet's phonebook, translating human-readable domain names into IP addresses that computers use to communicate. Despite its fundamental importance, DNS remains mysterious to many developers, leading to misconfigurations, troubleshooting challenges, and production incidents. This session demystifies DNS by explaining how it works at its core, from recursive queries and zone files to TTLs and record types, providing attendees with a solid foundation for understanding this critical infrastructure component. Beyond the fundamentals, this presentation explores how DNS operates in both traditional on-premises data centers and modern cloud environments. We'll examine real-world scenarios, common pitfalls, and best practices for DNS architecture in hybrid environments where cloud and on-premises systems must coexist. Whether you're migrating to the cloud, managing a hybrid infrastructure, or simply want to stop blaming DNS when things break, this session will equip you with the knowledge to design, implement, and troubleshoot DNS effectively. Attendees will learn: * DNS Fundamentals: How DNS resolution works, including recursive vs. iterative queries, DNS hierarchy, and the role of authoritative nameservers * DNS Record Types: Understanding A, AAAA, CNAME, MX, TXT, SRV, and other record types and when to use each * On-Premises DNS: Traditional DNS server configurations, zone management, and common patterns in enterprise data centers * Hybrid DNS Architecture: Best practices for connecting on-premises DNS with Azure, including conditional forwarding and DNS resolution in hybrid scenarios * Troubleshooting Techniques: Essential tools and methodologies for diagnosing DNS issues, including nslookup, and dig. * Common Pitfalls: Frequent DNS misconfigurations, caching issues, TTL considerations, and how to avoid production incidents