http://askubuntu.com/questions/640172/dns-routing-after-pptp-connection http://www.stgraber.org/2012/02/24/dns-in-ubuntu-12-04/ askubuntu.com/questions/137037/networkmanager-not-populating-resolv-conf

http://server-setting.info/ubuntu/first-setting-ubuntu-server.html

http://websetnet.com/how-to-build-a-dedicated-vpn-router/