PPTP VPN between Linux and XP

[Larsonlo]

Hopefully this is the right place to be asking this, but does anyone have any experience using Poptop PPTP server for linux. I am trying to set up a VPN between a linux server and a Windows XP client. I can get it to connect but it does not seem to do anything. It may not even really be connecting. This is what I get in the log file of the linux server:

Feb 15 22:58:10 pptpd[3371]: CTRL: Client 24.x.x.x control connection started
Feb 15 22:58:10 pptpd[3371]: CTRL: Starting call (launching pppd, opening GRE)
Feb 15 22:58:10 pppd[3372]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
Feb 15 22:58:10 pppd[3372]: pppd 2.4.3 started by root, uid 0
Feb 15 22:58:10 pppd[3372]: Using interface ppp0
Feb 15 22:58:10 pppd[3372]: Connect: ppp0 <--> /dev/pts/1
Feb 15 22:58:10 pptpd[3371]: GRE: Bad checksum from pppd.
Feb 15 22:58:10 pptpd[3371]: CTRL: Ignored a SET LINK INFO packet with real ACCMs!
Feb 15 22:58:10 kernel: PPP Deflate Compression module registered
Feb 15 22:58:10 pppd[3372]: Cannot determine ethernet address for proxy ARP
Feb 15 22:58:10 pppd[3372]: local IP address 192.168.1.2
Feb 15 22:58:10 pppd[3372]: remote IP address 192.168.1.12
Feb 15 22:58:53 pppd[3372]: LCP terminated by peer (1M-^_q1^@<M-Mt^@^@^@^@)
Feb 15 22:58:53 pppd[3372]: Modem hangup
Feb 15 22:58:53 pppd[3372]: Connection terminated.
Feb 15 22:58:53 pppd[3372]: Connect time 0.8 minutes.
Feb 15 22:58:53 pppd[3372]: Sent 137 bytes, received 5749 bytes.
Feb 15 22:58:53 pppd[3372]: Exit.

Let me know if you need more information. I'm not really sure what else to say. I have very little experience with VPNs. Would there be a better way to do it?

Thank you.

 

[wybnormal]

You are not connecting or more precisely, not keeping the connection. The error is two fold. First is the checksum error, this may or may not be fatel but the lack of a the ethernet address certainly is fatal. PopTop has a good debug page, have you look there yet?

http://pptpclient.sourceforge.net/howto-diagnosis.phtml#lcp_no_network_protocols

http://poptop.sourceforge.net/dox/diagnose-forwarding.phtml

How are you setting up the Linux side? command line or the GUI?

DId you configure the XP side to make sure that the user has remote access permission enabled?

MikeS

Find me at

http://www.packetattack.com

&quot;Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots.&quot;
Sun Tzu

 

[Larsonlo]

I used Webmin to setup the server side because I didn't know how to set it up from the command line. I have also tried connecting to the VPN server from a linux client using pptpconfig. It looks like it connects as well and works to ping, but also gives me errors in the log:

Feb 18 12:56:08 pptpd[22950]: CTRL: Client 24.x.x.x control connection started
Feb 18 12:56:09 pptpd[22950]: CTRL: Starting call (launching pppd, opening GRE)
Feb 18 12:56:09 pppd[22951]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
Feb 18 12:56:09 pptpd[22950]: GRE: Bad checksum from pppd.
Feb 18 12:56:09 pptpd[22950]: GRE: Received too short packet from pppd.
Feb 18 12:56:09 pppd[22951]: pppd 2.4.3 started by root, uid 0
Feb 18 12:56:09 pppd[22951]: Using interface ppp0
Feb 18 12:56:09 pppd[22951]: Connect: ppp0 <--> /dev/pts/1
Feb 18 12:56:09 pppd[22951]: Cannot determine ethernet address for proxy ARP
Feb 18 12:56:09 pppd[22951]: local IP address 192.168.1.3
Feb 18 12:56:09 pppd[22951]: remote IP address 192.168.1.13
Feb 18 12:58:06 pppd[22951]: LCP terminated by peer (User request)
Feb 18 12:58:06 pppd[22951]: Modem hangup
Feb 18 12:58:06 pppd[22951]: Connection terminated.
Feb 18 12:58:06 pppd[22951]: Connect time 2.0 minutes.
Feb 18 12:58:06 pppd[22951]: Sent 482 bytes, received 488 bytes.
Feb 18 12:58:06 pppd[22951]: Exit.
Feb 18 12:58:06 pptpd[22950]: CTRL: Client 24.x.x.x control connection finished

I also get this message in the terminal window when I run pptpconfig:

modinfo: could not find module ppp_mppe

I tried to turn off all mppe authentication to begin with. Could this be part of the problem?

I have looked at the debug page from Poptop. I just wasn't exactly sure what error I'm looking for. I will take a look at it some more. Is there any documentation on setting up the server from the command line? All I found were articles on setting up the PPTP client. How do I make sure the XP side has remote access permission enabled?
Thank you so much for your reply!