[已解决]连接VPN，类型PPTP，报错，求助

[fish.z]

我的是LInux MInt，VPN服务器为Windows Server 2008 R2提供 PPTP ，连接不能，报错如下，求助：

Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.3823] audit: op="connection-activate" uuid="e60e06d4-ebcf-452d-bef4-37cf0d0ecd4b" name="Hubei" pid=1748 uid=1000 result="success"
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.3921] vpn-connection[0x55a0d3b12610,e60e06d4-ebcf-452d-bef4-37cf0d0ecd4b,"Hubei",0]: Started the VPN service, PID 8868
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.3939] vpn-connection[0x55a0d3b12610,e60e06d4-ebcf-452d-bef4-37cf0d0ecd4b,"Hubei",0]: Saw the service appear; activating connection
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.4434] vpn-connection[0x55a0d3b12610,e60e06d4-ebcf-452d-bef4-37cf0d0ecd4b,"Hubei",0]: VPN connection: (ConnectInteractive) reply received
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.4448] vpn-connection[0x55a0d3b12610,e60e06d4-ebcf-452d-bef4-37cf0d0ecd4b,"Hubei",0]: VPN plugin: state changed: starting (3)
Oct 25 13:28:59 linda pppd[8877]: Plugin /usr/lib/pppd/2.4.7/nm-pptp-pppd-plugin.so loaded.
Oct 25 13:28:59 linda NetworkManager[6799]: Plugin /usr/lib/pppd/2.4.7/nm-pptp-pppd-plugin.so loaded.
Oct 25 13:28:59 linda pppd[8877]: pppd 2.4.7 started by root, uid 0
Oct 25 13:28:59 linda pppd[8877]: Using interface ppp0
Oct 25 13:28:59 linda NetworkManager[6799]: Using interface ppp0
Oct 25 13:28:59 linda NetworkManager[6799]: Connect: ppp0 <--> /dev/pts/2
Oct 25 13:28:59 linda systemd-udevd[8881]: link_config: autonegotiation is unset or enabled, the speed and duplex are not writable.
Oct 25 13:28:59 linda pppd[8877]: Connect: ppp0 <--> /dev/pts/2
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.4567] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/10)
Oct 25 13:28:59 linda pptp[8882]: nm-pptp-service-8868 log[main:pptp.c:353]: The synchronous pptp option is NOT activated
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.4618] devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Oct 25 13:28:59 linda NetworkManager[6799]: <info> [1540445339.4618] device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Oct 25 13:28:59 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 1 'Start-Control-Connection-Request'
Oct 25 13:28:59 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_disp:pptp_ctrl.c:781]: Received Start Control Connection Reply
Oct 25 13:28:59 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_disp:pptp_ctrl.c:815]: Client connection established.
Oct 25 13:29:00 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_rep:pptp_ctrl.c:259]: Sent control packet type is 7 'Outgoing-Call-Request'
Oct 25 13:29:00 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_disp:pptp_ctrl.c:900]: Received Outgoing Call Reply.
Oct 25 13:29:00 linda pptp[8894]: nm-pptp-service-8868 log[ctrlp_disp:pptp_ctrl.c:939]: Outgoing call established (call ID 16900, peer's call ID 63863).

[fish.z]

进度： 发现是因为开启了ufw防火墙。

现已开通1723端口， 那GRE协议穿透如何开放？

[fish.z]

sudo ufw allow proto gre from IP