我已经在我的 Raspberry Pi 盒子上安装了 pptpd（对于那些不知道的人来说，它是基于 Debian 的），它正在运行但无法正常工作 - 我无法连接。
这是有趣的日志-我尝试连接：
pi@raspberrypi ~ $ cat /var/log/syslog | grep pptpd | tail
Aug 21 11:32:24 raspberrypi pptpd[1770]: CTRL: Reaping child PPP[1771]
Aug 21 11:32:24 raspberrypi pptpd[1770]: CTRL: Client 77.253.47.194 control connection finished
Aug 21 12:17:21 raspberrypi pptpd[1855]: MGR: PPP binary /usr/sbin/pppd not executable
Aug 21 12:17:27 raspberrypi pptpd[1856]: CTRL: Client 77.253.47.194 control connection started
Aug 21 12:17:27 raspberrypi pptpd[1856]: CTRL: Starting call (launching pppd, opening GRE)
Aug 21 12:17:28 raspberrypi pptpd[1856]: CTRL: EOF or bad error reading ctrl packet length.
Aug 21 12:17:28 raspberrypi pptpd[1856]: CTRL: couldn't read packet header (exit)
Aug 21 12:17:28 raspberrypi pptpd[1856]: CTRL: CTRL read failed
Aug 21 12:17:28 raspberrypi pptpd[1856]: CTRL: Reaping child PPP[1857]
Aug 21 12:17:28 raspberrypi pptpd[1856]: CTRL: Client 77.253.47.194 control connection finished
和
pi@raspberrypi ~ $ cat /var/log/syslog | grep ppp | tail -n 25
Aug 21 11:32:24 raspberrypi pppd[1771]: but I couldn't find any suitable secret (password) for it to use to do so.
Aug 21 11:32:24 raspberrypi pptpd[1770]: GRE: read(fd=6,buffer=15b84,len=8196) from PTY failed: status = -1 error = Input/output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Aug 21 12:17:21 raspberrypi pptpd[1855]: MGR: PPP binary /usr/sbin/pppd not executable
Aug 21 12:17:27 raspberrypi pptpd[1856]: CTRL: Starting call (launching pppd, opening GRE)
Aug 21 12:17:27 raspberrypi pppd[1857]: pppd 2.4.5 started by root, uid 0
Aug 21 12:17:27 raspberrypi pppd[1857]: Using interface ppp0
Aug 21 12:17:27 raspberrypi pppd[1857]: Connect: ppp0 <--> /dev/pts/1
Aug 21 12:17:27 raspberrypi pppd[1857]: peer from calling number 77.253.47.194 authorized
Aug 21 12:17:27 raspberrypi pppd[1857]: kernel does not support PPP filtering
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: ifplugd 0.28 initializing.
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Using interface ppp0/00:00:00:00:00:00
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Using detection mode: IFF_RUNNING
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Initialization complete, link beat detected.
Aug 21 12:17:28 raspberrypi pppd[1857]: MPPE 128-bit stateless compression enabled
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Executing '/etc/ifplugd/ifplugd.action ppp0 up'.
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: client: Ignoring unknown interface ppp0=ppp0.
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Program executed successfully.
Aug 21 12:17:28 raspberrypi pppd[1857]: LCP terminated by peer (MPPE disabled)
Aug 21 12:17:28 raspberrypi pppd[1857]: Modem hangup
Aug 21 12:17:28 raspberrypi pppd[1857]: Connection terminated.
Aug 21 12:17:28 raspberrypi pppd[1857]: Connect time 0.1 minutes.
Aug 21 12:17:28 raspberrypi pppd[1857]: Sent 3630 bytes, received 6720 bytes.
Aug 21 12:17:28 raspberrypi pppd[1857]: Exit.
Aug 21 12:17:28 raspberrypi ifplugd(ppp0)[1882]: Link beat lost.
Aug 21 12:17:29 raspberrypi ifplugd(ppp0)[1882]: Exiting.
有人能从这些日志中看出任何线索吗？我对 ppp 和 pptp 都不太了解。
答案1
我自己在尝试连接到我的 Raspberry Pi 时也遇到了这个错误PPTP VPN。在搜索了“内核不支持 PPP 过滤”错误后，这似乎是一个需要编译进内核的选项（见最后一篇文章。）
要修复此问题，您需要使用不同的内核（或不同的发行版+内核），并将选项编译到内核中。您也可以尝试自己编译内核，并启用该选项（先进的）。