我使用此脚本https://raw2.github.com/suyan/Scripts/master/Setup/pptp.sh在 digitocean 上构建我的 VPN 服务器
但是，我无法使用我的 iPhone 或 Mac 连接到此 VPN 服务器。这里是/var/log/syslog说：
Oct 31 18:44:29 VPN pptpd[1422]: CTRL: Client xx.xx.xx.xx control connection started
Oct 31 18:44:29 VPN pptpd[1422]: CTRL: Starting call (launching pppd, opening GRE)
Oct 31 18:44:29 VPN pppd[1423]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
Oct 31 18:44:29 VPN pppd[1423]: pppd 2.4.5 started by root, uid 0
Oct 31 18:44:29 VPN pppd[1423]: Using interface ppp0
Oct 31 18:44:29 VPN pppd[1423]: Connect: ppp0 <--> /dev/pts/1
Oct 31 18:44:59 VPN pppd[1423]: LCP: timeout sending Config-Requests
Oct 31 18:44:59 VPN pppd[1423]: Connection terminated.
Oct 31 18:44:59 VPN pppd[1423]: Modem hangup
Oct 31 18:44:59 VPN pppd[1423]: Exit.
Oct 31 18:44:59 VPN pptpd[1422]: GRE: read(fd=6,buffer=b77c8480,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Oct 31 18:44:59 VPN pptpd[1422]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7)
Oct 31 18:44:59 VPN pptpd[1422]: CTRL: Reaping child PPP[1423]
Oct 31 18:44:59 VPN pptpd[1422]: CTRL: Client xx.xx.xx.xx control connection finished
任何人都可以帮忙吗？