PPTP VPN suddenly throwing Error 651
I am not sure exactly when this started happening but as of 6/5 it was still working. When I try to connect to my company's VPN (via PPTP) I get an Error 651. There is a dialog window that opens that says "all devices connected" ... not sure what is going on.I disabled all firewalls and even uninstalled Kaspersky. Still, same error.I re-created the VPN network connection, still same error.I uninstalled any of my recently installed programs (iTunes upgrade, etc.). Same issue.I performed a System Restore to 6/5 and I am still getting the same issue.I have this happening on my home desktop as well as my work laptop from two different locations (will try more when I get a chance) through both wired and wireless connections. As far as I know (and have been told) nothing has changed on my corporate LAN.The only things I see online for this error are related to PPPoE and firewalls ... not sure if PPPoE has anything to do with it at this point.Any other thoughts on what I can try?Info:Windows 7 RC, all latest critical and even some optional updates installedLaptop: Dell D830, 64bit, 4 GB RAM, 80 GB HDDDesktop: Pentium 4, 2 GB RAM, 120 GB HDDThanks,Jason
June 9th, 2009 7:53pm

You may already be aware of this since it working before but it doesn't hurt to ask... Is it set up for PPTP or IKEv2? I don't know if it's the same for 64-bit versions of Win7 but both beta 1 and RC build 7100 32-bit releases will default new VPN connections to IKEv2. To fix this, go to Control Panel -> Network and Internet -> Network Connections, find your connection profile, right click, select Properties -> Security and change Type of VPN to PPTP. -Gary
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June 10th, 2009 2:21am

Thanks for the reply, Gary. I did try this with no change. I even tried another VPN service (though not exactly a reliable test) with the same results.
June 10th, 2009 3:57pm

Ugh I hate pptp.My typical answers before trying anything else:- Did you reset your router?- What virus scanner/internet security suite is installed? More and more vendors add own network filters that block GRE traffic. If you check networking for your lan adapter are there other protocols installed as TCP/IPv6, TCP/IPv4, 2 Link-Layer Protocols?
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June 11th, 2009 9:36pm

Hahah ... yeah ... I am getting there too ...Yeah ... not ony have I reset my router, I have tried this in four different locations!For the security suite here is the order I have tried:1. Kaspersky Beta for Win 7 + It's firewall (Anit-Hacker)2. Kaspersky with Windows Firewall onlye3. Kaspersky NO firewall4. Kaspersky disabled5. Kaspersky uninstalled6. With and without Windows firewall enabled7. Now running Windows Firewall + Avira just to stay safe in the meantimeI have also tried with both LAN and WLAN adapters. Checked the protocols:WLAN:Client for MSQoS Packet SchedulerFile and Printer SharingVirtual Machine Network ServicesIP 4IP 6Link Layer ... ResponderLink Layer ... Mapper I/O DriverLAN:Same except I have unchecked IP6I am happy to run any packet capture/traces anyone would like!Thanks!
June 11th, 2009 10:24pm

jeah I'm just poking around too without the logs of the server.You could try to disable Receive Side Scaling in the advanced settings for your network adapter (actually that was a tip that once worked on the server side, but who knows).
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June 11th, 2009 10:44pm

You could try to disable Receive Side Scaling in the advanced settings for your network adapter No such option in the UI ... any idea on a netsh command for that one? I can research it if you don't know it offhand.
June 11th, 2009 10:54pm

set global rss=disabled
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June 11th, 2009 11:00pm

I did try the set global rss=disabled with no luck ... anyone know of any alternative PPTP clients that I can try?
June 15th, 2009 4:33pm

I don't suppose you can find a Windows update that was installed around the time the issue started? If so, you can try uninstalling that update.
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June 15th, 2009 7:33pm

I have the same problem after VirtualBox installation. Uninstall VirtualBox solve the problem for me.Do you have VirtualBox or other Virtualization software ?
June 18th, 2009 8:42pm

I'm in the same boat. I have two Dell laptops sitting on the same desk, connecting to the same wireless router, using the same MS VPN client to connect to the same VPN server using the same settings. Both are running Windows 7 RC. One of them works with no problem, the other is giving me the "All devices connected - Error 651 Your modem (or other device) is reporting an error" message. Firewall rules permit GRE and PPTP traffic and I've tried with the firewall disabled. I uninstalled and reinstalled the wireless drivers. Obviously if two laptops behave differently when all external factors are the same, the problem most likely lies in the one laptop. If anyone has any suggestions, or need more info to help, please let me know. -- Mark
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June 19th, 2009 11:57am

I dohave Virtual PC installed ... though it was working the entire time it had been installed ... I'll try removing it and see what happens.
June 19th, 2009 2:24pm

Removing Virtual PC 2007 SP1 totally fixed this. I will try and re-install (given that it worked before) and report back.
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June 19th, 2009 4:10pm

Removing Virtual PC 2007 SP1 totally fixed this. I will try and re-install (given that it worked before) and report back. On my machine VPC uninstallation didn't give expected results. The error still remains..
July 8th, 2009 7:48am

On my machine VPC uninstallation didn't give expected results. The error still remains.. Hmmm ... obvious questions:- Did you reboot after uninstalling?- Did you verify that everything did uninstall? (Check Programs and Features, check your network setting to see if the virtual machine network add-on is gone)- Did you try anything else others have suggested in this thread?- Do you have any other virtualization software installed (VM Ware, VirtualBox, etc.)?Sorry for the obvious questions but I am not sure what else to suggest myself.
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July 8th, 2009 2:27pm

Yes. Everything checked. At the first step I uninstalled "Microsoft Virtual PC 2007" then discovered that actually that one is installed as Windows Update (don't remeber #). ThenVirtual Windows XP removed as well. Everything removed, rebooted, no other virtualization software installed. Error still remains :)
July 8th, 2009 6:21pm

Just out of curiosity. I discovered this error at about the same time that I discovered the dll gpsvc.dll missing. Do you have that dll present in %windows%\system32? I understand it's part of group policy and cryptography, so it may be related.
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July 8th, 2009 10:27pm

Just out of curiosity. I discovered this error at about the same time that I discovered the dll gpsvc.dll missing. Do you have that dll present in %windows%\system32? I understand it's part of group policy and cryptography, so it may be related. Yes. I do have. Group Policy Client v6.1.7100.0
July 9th, 2009 5:32pm

Thank u guys. I would never thought VPC can cause such problems, especially because there was no symptoms for a long period of time after i've installed it(more then month), VPN worked fine.Also not only VPN crashed, my GPRS dial up didn't work, until i've uninstalled VPC, and my local area connection didn't work properlyeither.P.S: sorry for poor english.
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July 13th, 2009 7:28pm

Thank u guys. I would never thought VPC can cause such problems, especially because there was no symptoms for a long period of time after i've installed it(more then month), VPN worked fine.Also not only VPN crashed, my GPRS dial up didn't work, until i've uninstalled VPC, and my local area connection didn't work properlyeither.P.S: sorry for poor english.
July 13th, 2009 7:28pm

Thank you so much alain!! I uninstalled the filter driver of VirtualBox in the properties page of my NIC and all connections that uses WAN Miniport (L2TP, PPTP, PPPoE...) came back magically. You don't even need to uninstall the whole app; removing the driver is enough. But this problem is quite weird though. VirtualBox and L2TP VPN were both working quite well no matter if I dial first or turn the virtual pc on first. Then last night all connections based on WAN Miniport stopped working, showing the 651 error. I didn't install any driver, software or system update, so this problem seems completely random. The only unusual thing I was doing yesterday is that I ran VirtualBox as admin so I can access a physical partition, and then the VBoxSvc process didn't exit when I closed the application. Could this cause the network filter driver to malfunction? I also notice that it takes much longer time to establish a wireless connection. It shows I am connected to the AP, but no packets is coming through as if the system is waiting for something and it timed out.
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July 27th, 2009 9:29am

Thank you so much alain!!I uninstalled the filter driver of VirtualBox in the properties page of my NIC and all connections that uses WAN Miniport (L2TP, PPTP, PPPoE...) came back magically.You don't even need to uninstall the whole app; removing the driver is enough.But this problem is quite weird though. VirtualBox and L2TP VPN were both working quite well no matter if I dial first or turn the virtual pc on first. Then last night all connections based on WAN Miniport stopped working, showing the 651 error. I didn't install any driver, software or system update, so this problem seems completely random. The only unusual thing I was doing yesterday is that I ran VirtualBox as admin so I can access a physical partition, and then the VBoxSvc process didn't exit when I closed the application. Could this cause the network filter driver to malfunction?I also notice that it takes much longer time to establish a wireless connection. It shows I am connected to the AP, but no packets is coming through as if the system is waiting for something and it timed out. yes! I just wanted to confirm that Virutal Machine Network Service driver removal (not uncheck but uninstall) from NIC used items solved this problem. Thx to all you :)
July 29th, 2009 11:18pm

I had the same problem but I did not have VirtualBox installed. I found out that Connectify will cause it as well. After I uninstalled it, I was able to connect to my VPN networks.
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June 21st, 2011 9:38am

I can confirm that the same thing happens with the Connectify program. Uninstalling it solved the problem for me. I will try to install it again to see if I can tweak some settings to make it work side by side with my VPN connection. Per
June 22nd, 2011 9:06am

Thanks! I had the same problem. You saved me some time.
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July 7th, 2011 3:53am

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