L2TP VPN Issues - Intermittent errors resolved by reboot
Since installing Windows 7 (Action Pack version) and configuring a l2tp connection to an existing ciscoasa, there has been some intermittent connectivity (specifically reconnecting) issues with the tunnel. This exact setup work perfectly now on several other Vista and XP machines, but the same trouble is seen in one other Windows 7 install. The hardware (nic's, etc) from each machine vary. This is a vpn over ethernet->internet.The exact trouble is that after several connect - disconnect cycles, the vpn client will continuously error 692 when a connection is attempted.Disabling and re-enabling the network connection may sometimes resolve the problem, but rebooting always solves the problem.
September 30th, 2009 5:31am

Hi, Regarding this issue, I would like to share the following: List of Error Codes for Dial-up Connections or VPN Connections Considering that error 692 means that this issue is related to Hardware, please check the NIC: 1. Update the NIC driver which is for Widows 7. 2. Disable Saving Power function of the NIC: ============================= 1) Click Start, right click on Computer and choose Properties. 2) Click Device Manager. 3) Navigate to the NIC, right click on it and choose Properties. 4) Go to Power Management tab. 5) Please uncheck “Allow the computer to turn off this device to save power." 6) Restart the computer and check if it works. Thanks.Nicholas Li - MSFT
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October 5th, 2009 12:04pm

Thanks for the tips. I've tried different driver versions and various options, but considering that this same exact set of circumstances happened on two different machines rules out most of these types of problems. The problem has actually be resolved (mostly), see below.If anyone is interested in what the trouble turned out to be:1. The described scenario above is a residential setting. The internet access is cable service with a Linksys router. It turns out (through some serious digging!) that the Linksys routers external interface has a bad ingress buffer. It was missing inbound bytes transmitted from the cable modem! When those incomplete frames arrived at the pc they were seriously malformed. This dropped the L2TP tunnel, which in turn mangles the ____ out of Windows 7's RAS subsystem (See #2). Error 692 is one of many, many random RAS errors that have been displayed as a result of this. After two to three rounds of this trouble, RAS fails completely and required a reboot to reconnect to the vpn. This happened on two machines running the RTM build (Action Pack) of Windows 7 Pro 64bit. Windows Vista 32 bit and Windows XP SP2 32bit worked in the same environment, and were able to reconnect successfully each time with no reboot requried.2. Something in the Windows 7 RAS mechanism has changed significantly since Vista. The OS trouble is not solved at this point and has only been dampened by having replaced the faulty router. My opinion is that the error trapping piece of RAS is missing some reset functionality that existed in the prior version.-Michael Wells
October 8th, 2009 6:12pm

I wonder if the issue was really with your router. A couple of us over here have Windows 7 64 bit with an ASA 5510 and we have this exact same issue as you described but we don't have Linksys routers and in fact we have different routers. The only common denominator in all our cases would seem to be the ASA code and Windows 7. We also have a SonicWALL firewall, which does NOT have this issue, narrowing this down further to only the ASA. I can't help but wonder if the ASA isn't sending something bad to the client. Can you describe how to see these incomplete frames, and when exactly they appeared? Was it during disconnect? -Don
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December 23rd, 2009 4:00am

Don, The trouble continues... As you mentioned, Windows 7 64 bit + ASA 55XX using Windows RAS components seems to be mysteriously troubled. We removed the failing Linksys router after playing with network monitor and ping -l xxxx... the wan port buffer (I'm assuming it's actually buffered in hardware somehow) is not recording all data received. A frame with a 1024 bytes of icmp junk might leave the router on the internal network as a proper frame, but with only 1023 bytes of data. The (seriously) offending machine is a Dell Latitude 6400N with integrated Intel 82567LM gigabit ethernet. I have found that the Intel driver for Windows 7 x64 for the 82XXX series chips is either buggy or not properly conforming to the Windows 7 driver model. The driver flags the interface as up then down, then up and down repeatedly through the day. The link flapping doesn't seem to correspond to the vpn disconnects. This happens on both the physical ethernet port and on the corresponding docking station port on multiple switches. Beyond these troubles, the original issue isn't that the VPN won't stay up. But hey, we all understand that things happen. The issue is that after several disconnect / reconnect cycles Windows 7 RAS becomes despondent and flatly refuses to connect to ANY VPN until after a reboot. The error messages generated are numerous and inconsistent when this happens. I find this piece much more interesting and frustrating than crappy routers or bad nic drivers. I haven't been able to find any decent documentation on changes to RAS from XP->Vista->Windows 7. As a programmer, my guess is that something wasn't properly tested in the Windows 7 build of these components. As an occasional code-tester, I wouldn't be suprised if causing multiple transport-error disconnects and subsequent reconnectes wasn't tested at all. That's what tcp is for anyway, right? So we don't have to worry about "network issues" or "re-sending" data?? Ha! -Michael
December 28th, 2009 11:40pm

Hi All,I am having the same problem here with Windows 7 32bit and ZyXEL USG200 firewall. The problem appears on multiple machines with different NIC's, so it looks like a Windows 7 BUG...Jan
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February 3rd, 2010 4:28pm

Glad to see that I'm not alone! Since my last post I've reinstalled Windows 7 64bit on the primary offender and upgraded the ASA 5505 from 7.X to 8.X and still have the same exact trouble.
March 2nd, 2010 2:14am

I am experiencing the same problem with Windows 7 Pro 64bit. Users on 32bit XP have no issues. Apart from the VPN problem (after a few connects/disconnects), I also encounter the loss of certain network functionality. Other machines are unable to reach my network shares (the machine is unable to process request), and I am unable to reach profile mapped network drives (unexpected network error). I'm not 100% sure that the VPN connection is related to the network issues but it seems too much of a coincidence. After a reboot, both the VPN connection and the network functionality are restored to working order.
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April 28th, 2010 3:24am

Finally reply link worked. have you all tried upgrading the ASA to 8.2.2? I can't reproduce the issue after this upgrade. -Don
April 28th, 2010 4:47am

Afternoon All. We have the same issues with Win7 x64 native vpn client connecting to PIX 8.0(4) (latest version available for PIX 515e) ending up with error 692 and needing reboot. I’ld really appreciate any feedback from others to back up Don’s suggestion that upgrading to 8.2.2 (for ASA’s) has resolved this for multiple people… and also that no one else has found any other workarounds?? Much appreciated. James
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May 14th, 2010 6:21pm

Problem persists after ASA 8.2.2 upgrade. Still getting error 692, native Windows 7 x64 L2TP to ASA 5510 with client machine reboot required. Seems like there would at least be a process that could be restarted on the client side, but haven't found anything yet.
May 22nd, 2010 8:41am

Problem persists after ASA 8.2.2 upgrade. Still getting error 692, native Windows 7 x64 L2TP to ASA 5510 with client machine reboot required. Seems like there would at least be a process that could be restarted on the client side, but haven't found anything yet. Hm, what solved it then? Do you have all the latest windows updates? -Don
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May 24th, 2010 8:37am

Windows is fully up-to-date. Still unresolved by ASA 8.2.2 upgrade in my case. I've experienced this on two separate Windows 7 x64 machines (the only two that I've tried), since the upgrade.
May 25th, 2010 12:39am

Windows is fully up-to-date. Still unresolved by ASA 8.2.2 upgrade in my case. I've experienced this on two separate Windows 7 x64 machines (the only two that I've tried), since the upgrade. Oh sorry. maybe it was one of the unofficial builds we got from Cisco on top of 8.2.2. -Don
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May 25th, 2010 10:09am

Hi, for me it looks like installing the HotFix http://support.microsoft.com/kb/980399/en-us solved the issue even it is supposed to fix something else. Tried it on 3 Systems and now i can´t reproduce the error even after >40 connect/disconnect cycles. Can anyone try it and post the results?http://patrickgetzmann.spaces.live.com/blog
June 21st, 2010 5:40pm

Install the Hotfix solved the issue on my Win 7 laptop. Thanks, -Joshua
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July 13th, 2010 5:15am

Hi, It´s solved my problem as well. Very weird, but worked. Thanks.
September 22nd, 2010 12:24pm

Hi, for me it looks like installing the HotFix http://support.microsoft.com/kb/980399/en-us solved the issue even it is supposed to fix something else. Tried it on 3 Systems and now i can´t reproduce the error even after >40 connect/disconnect cycles. Can anyone try it and post the results? http://patrickgetzmann.spaces.live.com/blog This hotfix appears to have fixed my problem with "Anonymizer Universal", a security product/service and also a VPN from Anonymizer.com running within Windows 7, x64. My symptoms: For reasons unknown, my Internet connection is lost for about a minute or two, tens of times per day (laptop to wireless router to cable modem to cable provider). The router connection is NOT lost. The VPN software has to reconnect each time and will fail with an Error 692 within a few hours to 24 hours. Only a reboot restored the VPN. With NO logs (Windows, router, cable modem) revealing entries during these disconnect events, I am still researching this. After the hotfix, no failures have occurred following two successive 36 hour sessions. I hope to let the computer run for a week without a reboot to further test the fix.
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October 4th, 2010 6:35pm

Hi, for me it looks like installing the HotFix http://support.microsoft.com/kb/980399/en-us solved the issue even it is supposed to fix something else. Tried it on 3 Systems and now i can´t reproduce the error even after >40 connect/disconnect cycles. Can anyone try it and post the results? http://patrickgetzmann.spaces.live.com/blog This hotfix appears to have fixed my problem with "Anonymizer Universal", a security product/service and also a VPN from Anonymizer.com running within Windows 7, x64. My symptoms: For reasons unknown, my Internet connection is lost for about a minute or two, tens of times per day (laptop to wireless router to cable modem to cable provider). The router connection is NOT lost. The VPN software has to reconnect each time and will fail with an Error 692 within a few hours to 24 hours. Only a reboot restores the VPN. With NO logs (Windows, router, cable modem) revealing entries during these disconnect events, I am still researching this. After the hotfix, no failures have occurred following two successive 36 hour sessions. I hope to let the computer run for a week without a reboot to further test the fix.
October 4th, 2010 6:35pm

Hi, for me it looks like installing the HotFix http://support.microsoft.com/kb/980399/en-us solved the issue even it is supposed to fix something else. Tried it on 3 Systems and now i can´t reproduce the error even after >40 connect/disconnect cycles. Can anyone try it and post the results? http://patrickgetzmann.spaces.live.com/blog This hotfix appears to have fixed my problem with "Anonymizer Universal", a security product/service and also a VPN from Anonymizer.com running within Windows 7, x64. My symptoms: For reasons unknown, my Internet connection is lost for about a minute or two, tens of times per day (laptop to wireless router to cable modem to cable provider). The router connection is NOT lost. The VPN software has to reconnect each time and will fail with an Error 692 within a few hours to 24 hours. Only a reboot restores the VPN. With NO logs (Windows, router, cable modem) revealing entries during these disconnect events, I am still researching this. After the hotfix, no failures have occurred following two successive 36 hour sessions. I hope to let the computer run for a week without a reboot to further test the fix. Oct 14, 2010 Update: There is always something trying to update software or otherwise force a reboot, but I have run a session as long as four days without an Error 692. I have encountered other VPN related errors (all related to timeouts of one kind or another) but the VPN was able to manage these with a reconnect command. I have had NO Error 692 problems since the hotfix.
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October 5th, 2010 1:32am

Hi All, I am having the same problem here with Windows 7 32bit and ZyXEL USG200 firewall. The problem appears on multiple machines with different NIC's, so it looks like a Windows 7 BUG... Jan Same problem with Windows 7 64bit and the Zyxel USG200 firewall. KB930399 solved it !! jba
October 31st, 2010 9:35am

I got the hotfix and unzipped it. Still having the same problem. Do I need to actually run anything to make this work?? Where did it put the files?? I was offered no option to place them in a non-default location. Thanks Scott
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January 20th, 2011 11:44am

Hi Scott, you have to run the MSU File. Patrickhttp://patrickgetzmann.wordpress.com/
January 21st, 2011 3:25am

MSU refuse to install saying it's not applicatable to my comp 7600.16399.090723-1728_x86fre_client_en-us_Retail_Ultimate-GRMCULFRER_EN_DVD
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May 26th, 2011 7:24am

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