我无法让 VPNC 在运行于 Intel NUC 上的 Ubuntu 18.04 上运行。
我安装了network-manager-vpnc并network-manager-vpnc-gnome输入了所有要求的凭证。连接开始建立，但几秒钟后就断开了。
如果我需要在 Ubuntu 中进一步寻找解决方案，有人能给我指明合适的方向吗？”
Syslog 说：
autonegotiation is unset or enabled, the speed and duplex are not writable
然后，四行之后：
no ifupdown configuration found")
或者，错误在于 VPN 设置/连接？
我应该检查和/或尝试什么？
系统日志：
Blockquote
10月 20 21:39:10 madin-NUC7CJYH NetworkManager[733]: <info> [1540042750.9476] manager: NetworkManager state is now CONNECTED_SITE
10月 20 21:39:10 madin-NUC7CJYH dhclient[1064]: bound to 192.168.21.128 -- renewal in 2147483648 seconds.
10月 20 21:39:10 madin-NUC7CJYH NetworkManager[733]: <info> [1540042750.9535] policy: set 'Wired connection 1' (eno1) as default for IPv4 routing and DNS
10月 20 21:39:10 madin-NUC7CJYH NetworkManager[733]: <info> [1540042750.9548] device (eno1): Activation: successful, device activated.
10月 20 21:39:10 madin-NUC7CJYH NetworkManager[733]: <info> [1540042750.9566] manager: startup complete
10月 20 21:39:14 madin-NUC7CJYH NetworkManager[733]: <info> [1540042754.0001] manager: NetworkManager state is now CONNECTED_GLOBAL
10月 20 21:39:30 madin-NUC7CJYH NetworkManager[733]: <info> [1540042770.9807] audit: op="connection-activate" uuid="efb1116f-9a2a-45a0-8d68-e94814c44bfc" name="VPN 1" pid=1235 uid=1000 result="succe
10月 20 21:39:30 madin-NUC7CJYH NetworkManager[733]: <info> [1540042770.9927] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: Started the VPN service, PID 1864
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.0148] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: Saw the service appear; activating connec
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.0269] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN plugin: state changed: starting (3)
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.0276] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN connection: (ConnectInteractive) repl
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.3114] manager: (tun0): new Tun device (/org/freedesktop/NetworkManager/Devices/4)
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.3301] devices added (path: /sys/devices/virtual/net/tun0, iface: tun0)
10月 20 21:39:31 madin-NUC7CJYH NetworkManager[733]: <info> [1540042771.3307] device added (path: /sys/devices/virtual/net/tun0, iface: tun0): no ifupdown configuration found.
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: /usr/sbin/vpnc: authentication unsuccessful
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <warn> [1540042772.5197] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN plugin: failed: login-failed (0)
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <warn> [1540042772.5201] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN plugin: failed: connect-failed (1)
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <info> [1540042772.5213] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN plugin: state changed: stopping (5)
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <info> [1540042772.5216] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN plugin: state changed: stopped (6)
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <info> [1540042772.5271] vpn-connection[0x55bba549c220,efb1116f-9a2a-45a0-8d68-e94814c44bfc,"VPN 1",0]: VPN service disappeared
10月 20 21:39:32 madin-NUC7CJYH NetworkManager[733]: <info> [1540042772.5302] devices removed (path: /sys/devices/virtual/net/tun0, iface: tun0)