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

[Wylie Swanson]

Client is Windows XP Professional

I gave disabling chapms-v2 a shot -- I don't think auth is the problem.

This was the only thing that looked possibly different in the debug:

May 13 19:47:43 atry2 pptpd[1801]: GRE: read error: Bad file descriptor

Here's the output with chapms-v2 disabled:

May 13 19:47:29 atry2 pptpd[1800]: MGR: Manager process started
May 13 19:47:38 atry2 pptpd[1801]: MGR: Launching
/usr/local/sbin/pptpctrl to handle client
May 13 19:47:38 atry2 pptpd[1801]: CTRL: local address = 192.168.0.15
May 13 19:47:38 atry2 pptpd[1801]: CTRL: remote address = 192.168.0.224
May 13 19:47:38 atry2 pptpd[1801]: CTRL: pppd options file =
/etc/ppp/options.pptp
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Client 192.168.0.4 control
connection started
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 1)
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Made a START CTRL CONN RPLY
packet
May 13 19:47:38 atry2 pptpd[1801]: CTRL: I wrote 156 bytes to the
client.
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Sent packet to client
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 7)
May 13 19:47:38 atry2 pptpd[1801]: CTRL: 0 min_bps, 1525 max_bps, 32
window size
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Made a OUT CALL RPLY packet
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Starting call (launching pppd,
opening GRE)
May 13 19:47:38 atry2 pptpd[1801]: CTRL: pty_fd = 5
May 13 19:47:38 atry2 pptpd[1801]: CTRL: tty_fd = 6
May 13 19:47:38 atry2 pptpd[1802]: CTRL (PPPD Launcher): Connection
speed = 115200
May 13 19:47:38 atry2 pptpd[1801]: CTRL: I wrote 32 bytes to the client.
May 13 19:47:38 atry2 pptpd[1802]: CTRL (PPPD Launcher): local address =
192.168.0.15
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Sent packet to client
May 13 19:47:38 atry2 pptpd[1802]: CTRL (PPPD Launcher): remote address
= 192.168.0.224
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 15)
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Got a SET LINK INFO packet with
standard ACCMs
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 15)
May 13 19:47:38 atry2 pptpd[1801]: CTRL: Ignored a SET LINK INFO packet
with real ACCMs!
May 13 19:47:40 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 15)
May 13 19:47:40 atry2 pptpd[1801]: CTRL: Got a SET LINK INFO packet with
standard ACCMs
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Received PPTP Control Message
(type: 12)
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Made a CALL DISCONNECT RPLY
packet
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Received CALL CLR request
(closing call)
May 13 19:47:43 atry2 pptpd[1801]: CTRL: I wrote 148 bytes to the
client.
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Sent packet to client
May 13 19:47:43 atry2 pptpd[1801]: GRE: read error: Bad file descriptor
May 13 19:47:43 atry2 pptpd[1801]: CTRL: PTY read or GRE write failed
(pty,gre)=(-1,-1)
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Client 192.168.0.4 control
connection finished
May 13 19:47:43 atry2 pptpd[1801]: CTRL: Exiting now
May 13 19:47:43 atry2 pptpd[1800]: MGR: Reaped child 1801

-----Original Message-----
From: Alex King [mailto:alex at king.net.nz] On Behalf Of Alex King
Sent: Monday, May 13, 2002 6:55 PM
To: Wylie Swanson
Subject: Re: [pptp-server] GRE: Bad checksum from pppd ?


On Mon, May 13, 2002 at 06:14:32PM -0700, Wylie Swanson wrote:
> 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.
> 
....

What client is this?

What does the ppp debug look like? (you only have pptp output listed)

If you read my posts, I had similar symptoms, the client disconnects
after an apparantly successfull authentication.  In my case, disabling
chapms-v2 fixed my problems.  I suggest you give it a try with that
disabled on the server and see what you get.

Alex

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