Nighmarish situation with connecting to L2TP from windows 10

Question

facing a very weird issue with a number of windows 10 laptops in different geographic locations with connecting to a L2TP VPN Server with preshared key (Microsoft RRAS server).

One RRAS rras server is on-prem and other on AWS. On a good day people would be able to connect to both VPNs. All of a sudden some people would not be able to connect to either the on-prem VPN or AWS, some people would even face an issue with either of the VPNs that they may be able to connect but they loose internet connection as soon as they connect (probably a remote gateway issue). These issues are so random and any of them would start to happen on all these different laptops, no real pattern observed, the issues in some cases would go away after a while.

Already tried the registry hacks and other things from similar forums but no real solution in sight.

One important thing i would like to highlight is that we have mostly Macs in our environment and interestingly they have no issue connecting to all of our VPN servers at any give time (how ironic lol)

Answer 1

Hi

Did you can see from where the user connect from when it happen ? as usually random fail like that can be caused by the user router if VPN Passthrough is disabled (L2PT Passthrough is usually in that settings)

Example from a cisco/linksys;

If the setting is Enabled and the error happen, please make a wireshark to diagnose where the connection got a problem.

Thanks

Philippe

Answer 2

thanks for the tip but the issues i mentioned appear to be local to the machine, to give you a clear example, i have 3 windows laptops with me with all updates/drivers installed, and all connecting via my home wifi.

Two of them are able to connect to a particular l2tp VPN but the 3rd one doesn't

note that i have setup vpn profiles using the native/built-in vpn options in windows 10

i did run wireshark on the laptops and while i am not an expert with this product, i did notice that some "TCP re-transmission" occurrences on the laptop that is not able to connect

Answer 3

Hi ,

Thanks for your posting here. What's the exact error message when you cannot connect to VPN server? Also, you can check event log to see if there are any error code for us to do troubleshooting.

In addition, for random issue, it is hard for us to analyze from forum support level. Generally, we need to trace and monitor network traffic to analyze the cause when the issue occurs again. However, analysis of network traffic is beyond our forum support level and due to forum security policy, we have no such channel to collect user log information. So we recommend you open a case with MS Professional tech support service, they will help you open a phone or email case to Microsoft, so that you would get a technical support on a one-to-one basis while ensuring private information.

Here is the link:

https://support.microsoft.com/en-us/gp/customer-service-phone-numbers

Best Regards,
Candy

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Answer 4

thanks, i am getting error 800 in event viewer. Ok i will proceed to contact MS tech support.