nas openvpn conf client dev tun dev-type tun remote cn-bj1-kvlqs4ee.frp.cool 15150 tcp-client nobind persist-tun cipher AES-128-CBC data-ciphers AES-128-GCM:AES-128-CBC auth SHA1 verb 2 mute 3 push-peer-info ping 10 ping-restart 60 hand-window 70 se