All examples I have seen of configurations (/etc/network/interfaces) showed that you configure an interface and then underneath that gave the dns-* lines such as:auto eth0iface eth0 inet static        ...        dns-nameservers 127.0.0.2        dns-search example.com my.example.comNow I am aware that the DNS protocol is independent of the transport mechanism. Therefore it shouldn't be per-se wrong to add an IPv6 address on the dns-nameservers line.However, since I am also configuring the interface for IPv6 anyway, it made sense to add the dns-nameservers line there:iface eth0 inet6 static        ...        dns-nameservers ::2        dns-search example.com my.example.com... or did it? Because when resolvconf creates /etc/resolv.conf it simply ignores all the IPv6 DNS servers. It also seems to ignore dns-search and dns-domain. The only line it seems to honor is the dns-nameservers line from the IPv4 configuration for eth0.What is the correct method of configuring DNS servers?Further circumstantial evidence as to why it should be part of each respective iface stanza. Quote from man 8 resolvconf:The ifup(8)  program  can  be  used  to  configure  network   interfaces according to settings in /etc/network/interfaces(5).  To  make ifup push nameserver information to resolvconf when it configures  an  interface, add dns- lines to the relevant iface stanza in  /etc/network/interfaces. To add nameserver addresses add a line  beginning with dns-nameservers.
Ubuntu: How to configure DNS servers in /etc/network/interfaces correctly for resolvconf?
ubuntu;networking;dns;resolvconf