Liangxu Linux

Jun 22, 2023 · Fundamentals

Why Only 13 DNS Root Servers? History, Limits, and Modern Solutions

This article explains the DNS hierarchy, details the 13 official root servers, describes how priming queries work, why the 512‑byte UDP limit created a technical bottleneck, and how label compression, EDNS0, Anycast and server renaming have allowed the system to scale beyond the original constraints.