This post delves into the intricacies of DNS resolution within Linux systems and Kubernetes environments. It highlights the historical use of `resolv.conf` and `nsswitch.conf`, discussing the absence of a local DNS resolver daemon in traditional UNIX systems and the benefits that such a daemon could provide, including system-wide DNS caching. The Kubernetes DNS functionality is explored, especially the capability to resolve Kubernetes pod addresses to their respective IPs. This feature supports various applications such as testing unconventional DNS settings, issuing TLS certificates, and efficiently managing multiple services using a single IP address. Users are cautioned against employing `.local` and `.dev` domains due to their official TLD status and the potential for conflicts. The final note stresses the importance of following ICANN guidelines for private domain uses, referencing ongoing discussions in the IETF regarding internal TLDs.