In order to let our office to access the private network of our servers in IDC, I set up an OpenVPN server on 1.1.1.1, which is a server in IDC, and set up an OpenVPN client on 2.2.2.2, which is a server configured in DMZ of our office network, like this: IDC private network--OpenVPN server(1.1.1.1)--OpenVPN client(2.2.2.2)--Office private network But the OpenVPN connection auto-restarted very oft