whatis dns
DNS
Also known as: Domain Name System, resolver, /etc/resolv.conf
The system that translates hostnames like linuxdork.com into IP addresses, queried on Linux with tools like dig.
What Is DNS in Linux?
When a program looks up a name, glibc checks /etc/nsswitch.conf, usually tries /etc/hosts first, then asks the resolver listed in /etc/resolv.conf. On many distros that is systemd-resolved on 127.0.0.53.
Common record types are A (IPv4), AAAA (IPv6), CNAME (alias), MX (mail), and TXT. Most "the internet is down" problems turn out to be DNS.
Example
dig +short linuxdork.com
resolvectl statusLearn more about DNS
- DNS Explained DNS translates human-readable hostnames into IP addresses. This guide covers how the resolution process works, the most important record types, and the Linux tools used to query and debug DNS.
- dig Explained: Diagnosing DNS From the Command Line Half of all networking problems are DNS problems, and dig is how you find out which half. Here is how to query specific servers, trace a lookup from the root, and read what comes back.
- systemd-resolved Explained: Why /etc/resolv.conf Is a Symlink Now What systemd-resolved does, why 127.0.0.53 appears in resolv.conf, how split DNS works, and how to actually configure or disable it.
- Unbound: Running Your Own Recursive DNS Resolver Pi-hole filters. A forwarder caches. Unbound resolves from the root servers itself, which means no provider sees your queries at all. Setup, DNSSEC, and the one setting that makes it feel slow when it is not.
- Pi-hole and Network-Wide DNS Filtering Blocking ads at the DNS layer covers every device on the network including the ones that cannot run an extension. Here is how it works, what it cannot do, and how to avoid making yourself the network outage.