Install Network Manager Plugin for OpenVPN on Ubuntu

1. Install Network Manager Ubuntu
# apt-get install network-manager-openvpn

2. Config OpenVPN Connection

2.1 Open "Network Connection" then Click "Add" button

2.2 Choose a Connection Type "OpenVPN"

2.3 Edit VPN Connection

Gateway: VPN Server Name
Authentication Type: Password with Certificates (TLS)
Username: VPN Username
Password: VPN Password
User Certificate:  xxx.crt
CA Certificate: ca.crt
Private Key: xxx.key
then click "Advanced Option"

2.4 Edit Advanced Option

Select Option
- Use LZO data compression
- Use a TAP device