https://peng.fyi/tags/dns/ Recent content in DNS on Hugo -- gohugo.io en map[name:Peng Zhang] map[name:Peng Zhang] Peng Zhang Wed, 10 Jun 2026 00:00:00 +0000 https://peng.fyi/post/trailing-dot-dns/ Wed, 10 Jun 2026 00:00:00 +0000 map[name:Peng Zhang] https://peng.fyi/post/trailing-dot-dns/ If you build software that runs in someone else's environment, anything that isn't a SaaS you operate yourself, there's a small, innocent-looking line of code you should think twice about writing: 1hostname = hostname + "." Appending a trailing dot to a domain name before you resolve it feels "more correct" when you own the domain name. It can even be a performance optimization (more on that later). But in software you don't control the runtime for, it can result in a hard failure, and you won't see it in testing, because it only breaks in DNS environments that look nothing like yours.