Inria UCL UCL Infoblox INSA-Lyon & Inria This document outlines guidance for Internet of Things (IoT) manufacturers regarding the implementation of DNS stub resolver software on devices, and for the management zones used for purposes such as device configuration and software upgrades. It aims to mitigate security threats, enhance privacy, and to address operational security challenges. DNS resolution between devices and management zone servers depends upon DNS services within operator networks, and these services and operator networks can be impacted by device behavior. Hence this document also provides guidance to network operators that deploy IoT devices to mitigate the specific risks identified in this document and take advantage of improved DNS security mechanisms provided by manufacturers.