How to get configured DNS servers in Ubuntu

In some situations could be needed to know exactly which DNS server is being used by an Ubuntu host. There are several ways to get this info, however the best option I have found is to use the systemd service systemd-resolve. This service is in charge of the name resolution of the local applications.

You can use it executing systemd-resolve --status or just resolvectl. The command will return the DNS servers configured in each network interface, and which one is currently being used.

This is an example:

yvoictra|saturn:~$ systemd-resolve --status
Global
       Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub

Link 2 (eth0)
    Current Scopes: DNS
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 8.8.4.4
       DNS Servers: 192.168.1.210 8.8.4.4

Link 3 (wlan0)
    Current Scopes: DNS
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 8.8.8.8
       DNS Servers: 8.8.8.8 8.8.4.4

And that’s all. It’s quite simple in Ubuntu to get this useful information.