http://d.hatena.ne.jp/chibatching/20130428/1367154401 http://www.clear-code.com/blog/2010/11/19.html http://blog.kazu634.com/2013/09/20/how_to_install_openvpn_under_ubuntu_1204/ http://www.openvpn.jp/document/how-to/ http://www.slsmk.com/g…