我按照https://wiki.archlinux.org/index.php/PPTP_Server上的说明使用 pptpd 设置 pptp vpn 服务器。
一切完成后，我无法连接到服务器。我发现 的输出中没有任何 ppp 虚拟适配器ifconfig。但是 pptpd 服务的日志没有错误，并且 pptpd 进程正在运行。
客户端日志如下：
Apr 06 09:31:34 root pppd[540]: Using interface ppp1
Apr 06 09:31:34 root pppd[540]: Connect: ppp1 <--> /dev/pts/3
Apr 06 09:31:34 root pptp[541]: anon log[main:pptp.c:314]: The synchronous pptp option is NOT activated
Apr 06 09:31:35 root pptp[546]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request'
Apr 06 09:31:35 root pptp[546]: anon log[ctrlp_disp:pptp_ctrl.c:739]: Received Start Control Connection Reply
Apr 06 09:31:35 root pptp[546]: anon log[ctrlp_disp:pptp_ctrl.c:773]: Client connection established.
Apr 06 09:31:36 root pptp[546]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request'
Apr 06 09:31:36 root pptp[546]: anon log[ctrlp_disp:pptp_ctrl.c:858]: Received Outgoing Call Reply.
Apr 06 09:31:36 root pptp[546]: anon log[ctrlp_disp:pptp_ctrl.c:897]: Outgoing call established (call ID 0, peer's call ID 0).
Apr 06 09:31:36 root pptp[546]: anon log[pptp_read_some:pptp_ctrl.c:544]: read returned zero, peer has closed
Apr 06 09:31:36 root pptp[546]: anon log[callmgr_main:pptp_callmgr.c:258]: Closing connection (shutdown)
Apr 06 09:31:36 root pptp[546]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
Apr 06 09:31:36 root pptp[546]: anon log[pptp_read_some:pptp_ctrl.c:544]: read returned zero, peer has closed
Apr 06 09:31:36 root pptp[546]: anon log[call_callback:pptp_callmgr.c:79]: Closing connection (call state)
Apr 06 09:31:36 root pppd[540]: Modem hangup
Apr 06 09:31:36 root pppd[540]: Connection terminated.
Apr 06 09:31:36 root pppd[540]: Exit.
谁能告诉我它有什么问题？谢谢！