Topic: PPTP connections have been unreliable since E-Smith 5.5

[shmeg]

trying to vpn from xp machine through 6.01 gateway to another 6.01 box. No luck yet others are working.
Have three boxes now behaving the same as described above after upgrading from 5.6 to 6.01.

Log files show
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: MGR: Launching /usr/sbin/pptpctrl to handle client
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: local address = 10.0.0.254
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: remote address = 10.0.0.246
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: pppd speed = 460800
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: pppd options file = /etc/ppp/options.pptpd
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Client 203.220.28.66 control connection started
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Received PPTP Control Message (type: 1)
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Made a START CTRL CONN RPLY packet
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: I wrote 156 bytes to the client.
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Sent packet to client
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Received PPTP Control Message (type: 7)
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Set parameters to 1525 maxbps, 64 window size
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Made a OUT CALL RPLY packet
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Starting call (launching pppd, opening GRE)
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: pty_fd = 5
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: tty_fd = 6
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: I wrote 32 bytes to the client.
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Sent packet to client
Jan 13 09:55:12 sff-sme-01 pptpd[8901]: CTRL (PPPD Launcher): Connection speed = 460800
Jan 13 09:55:12 sff-sme-01 pptpd[8901]: CTRL (PPPD Launcher): local address = 10.0.0.254
Jan 13 09:55:12 sff-sme-01 pptpd[8901]: CTRL (PPPD Launcher): remote address = 10.0.0.246
Jan 13 09:55:12 sff-sme-01 pppd[8901]: pppd 2.4.2b1 started by root, uid 0
Jan 13 09:55:12 sff-sme-01 pppd[8901]: Starting negotiation on /dev/pts/2
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Received PPTP Control Message (type: 15)
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Got a SET LINK INFO packet with standard ACCMs
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: GRE: read(fd=6,buffer=80559a0,len=8260) from network failed: status = -1 error = Protocol not available
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: GRE read or PTY write failed (gre,pty)=(6,5)
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Client 203.220.28.66 control connection finished
Jan 13 09:55:12 sff-sme-01 pptpd[8900]: CTRL: Exiting now
Jan 13 09:55:12 sff-sme-01 pptpd[28817]: MGR: Reaped child 8900
Jan 13 09:55:12 sff-sme-01 pppd[8901]: Modem hangup
Jan 13 09:55:12 sff-sme-01 pppd[8901]: Connection terminated.
Jan 13 09:55:12 sff-sme-01 pppd[8901]: Exit.


any help would be appreciated!

[CharlieBrady]

I had no problems using v5.6, but since  upgrading to v6.01 I have not been able to connect.

I believe it may have something to do with the fact that I have an AMD Athlon XP 2800+ CPU.

Correct.

Aug  6 08:37:50 fs1 pppd[8833]: MPPE required, but kernel has no support.
[...]
I have tried all possible client configuratons.

Your problem isn't at the client end.

You need to have a ppp-modules RPM installed which matches the architecture of your kernel. That probably means the 'athlon' variant of each, but the 'i686' of both would also work.

You should be able to do "modprobe ppp_mppe" without error.

[koopmann]

I also have some problems with pptp from behind SME 6.01 (at home) to SME 6 (at work), but the problem seams to be related to winXPpro. Connecting from a win98SE does not give any problems at all. From an XPpro I sometimes can connect. If I succeed in connecting, I can se the e-bays and printers, but I can’t se the content and I can’t connect to the printers.
I hope this information can help somebody to localize the problem.
Birger Koopmann

[CharlieBrady]

From an XPpro I sometimes can connect. If I succeed in connecting, I can se the e-bays and printers, but I can’t se the content and I can’t connect to the printers.

That gives a hint that it might be related to TCP MSS (maximum segment size). Someone might like doing some experiments with the iptables clamp-mss option.

[lpbbear]

I have been lurking here and following the PPTP posts and thought maybe I could add a bit of info that may be of interest to someone.
I have 4 SME Servers in production use at customers. All are ver 6.01 and 3 are setup to do PPTP VPN. The 4th is using a Windows server with PPTP access and an SME Server for email. Because there is a builtin PPTP client in WinXP Pro, I had been using a copy of that to connect to my customers system. Unfortunately, with 2 systems, I was having strange connection problems. The other 2 worked fine. I spent quite a bit of time trying to diagnose what was wrong and never could find a solution...until recently.
I normally can't stand even using WIndows for anything but since there wasn't an easy to use VPN client in any Linux distribution, I continued to deal with WinXP on a spare system for this task.
Recently Xandros released version 3.0 Deluxe and included an easy to use VPN client in the release. Much to my surprise the Xandros client not only worked perfectly with EVERY customers system, (including the MS PPTP server) but it actually "feels" faster and smoother. I have now dumped any trace of Windows from my systems and am happily using SME Server and Xandros for my needs.
Perhaps the issues some of you are experiencing have absolutely nothing to do with SME Server 6.01 and more to do with Windows.