[pptp-server] GRE: Bad checksum from pppd ?

[Wylie Swanson]

I am not sure what is causing this problem or if "GRE: Bad checksum from
pppd" is the terminating error.  This is running on a 2.4.18 patched
kernel with mppe and mschap2 and PoPToP.  Authentication appears to be
working, but the connection is lost immediately after successful
authentication.

May 13 17:10:15 myserver pptpd[1658]: MGR: Launching
/usr/local/sbin/pptpctrl to handle client
May 13 17:10:15 myserver pptpd[1658]: CTRL: local address = 192.168.0.15
May 13 17:10:15 myserver pptpd[1658]: CTRL: remote address =
192.168.0.225
May 13 17:10:15 myserver pptpd[1658]: CTRL: pppd options file =
/etc/ppp/options.pptp
May 13 17:10:15 myserver pptpd[1658]: CTRL: Client 192.168.0.4 control
connection started
May 13 17:10:15 myserver pptpd[1658]: CTRL: Received PPTP Control
Message (type: 1)
May 13 17:10:15 myserver pptpd[1658]: CTRL: Made a START CTRL CONN RPLY
packet
May 13 17:10:15 myserver pptpd[1658]: CTRL: I wrote 156 bytes to the
client.
May 13 17:10:15 myserver pptpd[1658]: CTRL: Sent packet to client
May 13 17:10:15 myserver pptpd[1658]: CTRL: Received PPTP Control
Message (type: 7)
May 13 17:10:15 myserver pptpd[1658]: CTRL: 0 min_bps, 1525 max_bps, 32
window size
May 13 17:10:15 myserver pptpd[1658]: CTRL: Made a OUT CALL RPLY packet
May 13 17:10:15 myserver pptpd[1658]: CTRL: Starting call (launching
pppd, opening GRE)
May 13 17:10:15 myserver pptpd[1658]: CTRL: pty_fd = 5
May 13 17:10:15 myserver pptpd[1658]: CTRL: tty_fd = 6
May 13 17:10:15 myserver pptpd[1659]: CTRL (PPPD Launcher): Connection
speed = 115200
May 13 17:10:15 myserver pptpd[1658]: CTRL: I wrote 32 bytes to the
client.
May 13 17:10:16 myserver pptpd[1659]: CTRL (PPPD Launcher): local
address = 192.168.0.15
May 13 17:10:16 myserver pptpd[1658]: CTRL: Sent packet to client
May 13 17:10:16 myserver pptpd[1659]: CTRL (PPPD Launcher): remote
address = 192.168.0.225
May 13 17:10:16 myserver pptpd[1658]: GRE: Bad checksum from pppd
May 13 17:10:16 myserver pptpd[1658]: CTRL: Received PPTP Control
Message (type: 15)
May 13 17:10:16 myserver pptpd[1658]: CTRL: Got a SET LINK INFO packet
with standard ACCMs
May 13 17:10:19 myserver pptpd[1658]: CTRL: Received PPTP Control
Message (type: 15)
May 13 17:10:19 myserver pptpd[1658]: CTRL: Ignored a SET LINK INFO
packet with real ACCMs!
May 13 17:10:19 myserver pptpd[1658]: CTRL: Received PPTP Control
Message (type: 15)
May 13 17:10:19 myserver pptpd[1658]: CTRL: Got a SET LINK INFO packet
with standard ACCMs
May 13 17:10:22 myserver pptpd[1658]: Error reading from pppd:
Input/output error
May 13 17:10:22 myserver pptpd[1658]: CTRL: GRE read or PTY write failed
(gre,pty)=(6,5)
May 13 17:10:22 myserver pptpd[1658]: CTRL: Client 192.168.0.4 control
connection finished
May 13 17:10:22 myserver pptpd[1658]: CTRL: Exiting now
May 13 17:10:22 myserver pptpd[1508]: MGR: Reaped child 1658

Thoughts?



Here's some additional

/etc/ppp/options.pptp:
#debug
lock
auth
+chap
+chapms     
+chapms-v2     
mppe-40     
mppe-128     
mppe-stateless  


TIA