Resolvconf settings

Typical format of resolv.conf generated by resolvconf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver ...

The resolveconf setting file is /etc/resolvconf/resolv.conf.d/head

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

If you edit the resolv.conf manually, it will be overwritten automatically after restarting network. So to change the resolv.conf permanently, you should change the /etc/resolvconf/resolv.conf.d/head file.

Add a line at the end of the head file like

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 1.1.1.1

Then reload the resolv.conf and restart the network.

resolvconf -u
/etc/init.d/networking restart