networking-mlnx-common network-manager-pptp
networking-mlnx-eswitchd network-manager-pptp-gnome
network-manager network-manager-ssh
network-manager-dev network-manager-ssh-gnome
network-manager-gnome network-manager-strongswan
network-manager-iodine network-manager-vpnc
network-manager-iodine-gnome network-manager-vpnc-gnome
network-manager-openconnect netwox
network-manager-openconnect-gnome netwox-doc
network-manager-openvpn
这些都装了，重启过了之后还是点击不了。
然后我在系统配置网络中点击加号添加了一个vpn以pptp方式连接的，vpn高级设置中只选中PAP,CHAP这两种。但是还是连接失败。查看syslog日志。
以下是syslog日志中的打印的：
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.6920] keyfile: update /etc/NetworkManager/system-connections/workVPN (860408e2-4c2e-4bab-a3b2-dc54d747ca69,"workVPN")
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.7154] vpn-connection[0x1833820,860408e2-4c2e-4bab-a3b2-dc54d747ca69,"workVPN",0]: VPN connection: (ConnectInteractive) reply received
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: ** Message: pppd started with pid 8096
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.7273] vpn-connection[0x1833820,860408e2-4c2e-4bab-a3b2-dc54d747ca69,"workVPN",0]: VPN plugin: state changed: starting (3)
Apr 6 17:03:30 litera-Inspiron-N4030 pppd[8096]: Plugin /usr/lib/pppd/2.4.7/nm-pptp-pppd-plugin.so loaded.
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: Plugin /usr/lib/pppd/2.4.7/nm-pptp-pppd-plugin.so loaded.
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (plugin_init): initializing
Apr 6 17:03:30 litera-Inspiron-N4030 pppd[8096]: pppd 2.4.7 started by root, uid 0
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 3 / phase 'serial connection'
Apr 6 17:03:30 litera-Inspiron-N4030 pppd[8096]: Using interface ppp0
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: Using interface ppp0
Apr 6 17:03:30 litera-Inspiron-N4030 pppd[8096]: Connect: ppp0 <--> /dev/pts/20
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: Connect: ppp0 <--> /dev/pts/20
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 5 / phase 'establish'
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: nm_device_get_device_type: assertion 'NM_IS_DEVICE (self)' failed
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.7472] manager: (ppp0): new Generic device (/org/freedesktop/NetworkManager/Devices/13)
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.7696] devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Apr 6 17:03:30 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005410.7713] device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Apr 6 17:03:30 litera-Inspiron-N4030 pptp[8106]: nm-pptp-service-8078 log[main:pptp.c:350]: The synchronous pptp option is NOT activated
Apr 6 17:03:30 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 1 'Start-Control-Connection-Request'
Apr 6 17:03:30 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_disp:pptp_ctrl.c:781]: Received Start Control Connection Reply
Apr 6 17:03:30 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_disp:pptp_ctrl.c:815]: Client connection established.
Apr 6 17:03:31 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 7 'Outgoing-Call-Request'
Apr 6 17:03:31 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_disp:pptp_ctrl.c:900]: Received Outgoing Call Reply.
Apr 6 17:03:31 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_disp:pptp_ctrl.c:939]: Outgoing call established (call ID 23880, peer's call ID 5376).
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 6 / phase 'authenticate'
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 8 / phase 'network'
Apr 6 17:03:34 litera-Inspiron-N4030 pppd[8096]: LCP terminated by peer (peer refused to authenticate)
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: LCP terminated by peer (peer refused to authenticate)
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 5 / phase 'establish'
Apr 6 17:03:34 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[pptp_read_some:pptp_ctrl.c:586]: read returned zero, peer has closed
Apr 6 17:03:34 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[callmgr_main:pptp_callmgr.c:269]: Closing connection (shutdown)
Apr 6 17:03:34 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 12 'Call-Clear-Request'
Apr 6 17:03:34 litera-Inspiron-N4030 pppd[8096]: Modem hangup
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: Modem hangup
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 11 / phase 'disconnect'
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: Connection terminated.
Apr 6 17:03:34 litera-Inspiron-N4030 pppd[8096]: Connection terminated.
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: Terminated ppp daemon with PID 8096.
Apr 6 17:03:34 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[pptp_read_some:pptp_ctrl.c:586]: read returned zero, peer has closed
Apr 6 17:03:34 litera-Inspiron-N4030 pptp[8116]: nm-pptp-service-8078 log[call_callback:pptp_callmgr.c:84]: Closing connection (call state)
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: <error> [1523005414.8124] platform-linux: do-change-link[14]: failure changing link: failure 19 (没有那个设备)
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: <warn> [1523005414.8125] device (ppp0): failed to disable userspace IPv6LL address handling
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005414.8164] vpn-connection[0x1833820,860408e2-4c2e-4bab-a3b2-dc54d747ca69,"workVPN",0]: VPN service disappeared
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_phasechange): status 1 / phase 'dead'
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: ** Message: nm-pptp-ppp-plugin: (nm_exit_notify): cleaning up
Apr 6 17:03:34 litera-Inspiron-N4030 pppd[8096]: Exit.
Apr 6 17:03:34 litera-Inspiron-N4030 NetworkManager[772]: <info> [1523005414.8395] devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
查了好多资料，问题还是没解决。有没有遇到这种问题的同学，想请教一下啊
