BT5 添加网络管理器：
apt-get install network-manager-gnome
apt-get install network-manager-pptp
apt-get install network-manager-vpnc
cp /etc/network/interfaces /etc/network/interfaces.backup
echo "auto lo" > /etc/network/interfaces
echo "iface lo inet loopback" >> /etc/network/interfaces
service network-manager restart
右上角出现网络管理图标，点击进行管理
