resolv.confの内容が勝手に書き換わるのを防ぐには

/etc/resolvconf/resolv.conf.d/baseに/etc/resolv.confの内容を書く。

% sudo resolvconf -u

http://askubuntu.com/questions/157154/how-do-i-include-lines-in-resolv-conf-that-wont-get-lost-on-reboot