http://www.enterprisenetworkingplanet.com/netos/article.php/10951_3710641_2
http://www.enterprisenetworkingplanet.com/img/examples/ubuntu_server_config_diff.html
http://www.enterprisenetworkingplanet.com/netos/article.php/3709221
http://lists.netisland.net/archives/plug/plug-2008-06/msg00189.html