The VPN server in Linux appears pty read or GRE write failed problem

When the REHL department builds a pptp vpn server connection (619 errors). Check the system log [cat / var / log / messages | grep pptpd] and find that the following log content will appear every time the connection fails:


GRE: read (fd = 6, buffer = 80504c0, len = 8196) from PTY failed: status = -1 error = Input / output error, usually caused by unexpected termination of pppd, check option syntax and pppd logs
CTRL: PTY read or GRE write failed (pty, gre) = (6,7)
CTRL: Reaping child PPP [13354]
CTRL: Client XXX.XXX.XXX.XXX control connection finished

So turn on the debug mode, modify the / etc / ppp / pptp-options file, find


#Cancel the following line before #
debug
#carried out
service pptpd restart

Cancel the comment before the line and restart the pptpd service to enter debug mode

After analyzing the logs, it was found that the logwtmp version was inconsistent with the pptpd version, so opened the /etc/pptpd.conf file and found

logwtmp

After commenting out logwtmp, restart pptpd and everything will return to normal after connecting again.
By default, the proxyarp (in / etc / ppp / pptp-options) function is enabled. After each abnormal disconnection, execute the following command:

#windows
arp -d
#linux
sudo arp -d -a