Photo by Uzoma Ozurumba, CC BY-SA 4.0, no changesI’m generally a big fan of encrypted DNS for the security it provides with negligible performance impact. But I recently found out the hard way that DNS over TLS/HTTPS can deadlock with Network Time Protocol (NTP) on embedded devices without a battery-backed real-time clock. Many low-cost routers lack a battery for keeping time during power loss. Af
![Encrypted DNS + NTP = Deadlock](https://cdn-ak-scissors.b.st-hatena.com/image/square/390000ec8487df0c56d2472db855183c987d3b0d/height=288;version=1;width=512/https%3A%2F%2Fmiro.medium.com%2Fv2%2Fresize%3Afit%3A1200%2F0%2AbhtG697nF1vN_USW.jpg)