Pptp server failed to connect with windows pptp client

Installing and Using OpenWrt
1

Hi, I setup pptp server in the openwrt (though the command line)

When I try to use a windows client to connect to the server, I got an error in the system log:

Sun Nov 14 15:29:20 2021 daemon.info pptpd[28245]: CTRL: Client www.xxx.yyy.zzz control connection started
Sun Nov 14 15:29:20 2021 daemon.info pptpd[28245]: CTRL: Starting call (launching pppd, opening GRE)
Sun Nov 14 15:29:20 2021 daemon.err pppd[28246]: invalid parameter '1' for mppe option
Sun Nov 14 15:29:20 2021 daemon.err pptpd[28245]: GRE: read(fd=6,buffer=421478,len=8196) from PTY failed: status = -1 error = I/O error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
Sun Nov 14 15:29:20 2021 daemon.err pptpd[28245]: CTRL: PTY read or GRE write failed (pty,gre)=(6,7)
Sun Nov 14 15:29:20 2021 daemon.debug pptpd[28245]: CTRL: Reaping child PPP[28246]
Sun Nov 14 15:29:20 2021 daemon.info pptpd[28245]: CTRL: Client www.xxx.yyy.zzz control connection finished

In the Windows client side, I see an 809 error, which means it can't connect to the pptp server.

Any idea about how to fix this issue? Thanks.

My openwrt side of setting is mainly followed by this wiki page

[OpenWrt Wiki] PPTP server — https://openwrt.org/docs/guide-user/services/vpn/pptp/server
and
PPTP server on LEDE router WRT3200ACM - Installing and Using OpenWrt / Network and Wireless Configuration - OpenWrt Forum — PPTP server on LEDE router WRT3200ACM

2

Having the exact same issue, and followed the same PPTP guide.

Altho you have the invalid parameter '1' for mppe option I don't, but the rest is the same.

I couldn't yet figure out why its happening.

3

Although I cannot answer the question about why you're having this issue, I do think it is worth commenting to say the following:

PPTP is not secure. It has been deprecated on many platforms because there is no practical security with this protocol (it is extremely easy to hack). I would highly recommend disabling the PPTP server and finding a better (more secure, more modern, better supported) solution such as Wireguard or OpenVPN (or several other protocols).

1 Like
4

To be fair, the issue appears to be Windows specific as the instruction still works for me with the latest stable OpenWrt release serving both client and server.