Windows 10 Update 2022-01 Breaks VPN

Question

Today's update seems to have broken our company's VPN. We're using the built-in Windows client L2TP with digital certificate. All staff who have installed the update are experiencing the issue and uninstalling the update fixes it.

What happens when clicking Connect on the VPN is I'm immediately shown this message:

"The L2TP connection attempt failed because the security layer encountered a processing error during the initial negotiations with the remote computer."

Event viewer also logs EventID 20227 with RAS code 789.

I read somewhere the update includes a security patch to IKE. I assume that has something to do with it.

Any ideas?

Answer 1

Hi, my name is Anderson Souza, I hope I can help you with your issue.

I believe that your question will be better evaluated if it is posted in a more suitable location such as the new Microsoft Q&A forum that is replacing the old TechNet. As it is a question aimed at infrastructure administrators that have more knowledge about enterprise network technologies like VPN, I believe that you will get better results there, since this forum here is intended for home Windows users. Please, check the link below:

https://docs.microsoft.com/en-us/answers/products/

Another tip that I can give you at the moment that may help you to avoid future problems of this type is using WSUS in your company, there are documentations with best practices for using WSUS, such as creating a group of update approval machines.

Answer 2

Is the flawed KB5009543 that disables L2TP VPN connections going to be fixed? This is a countrywide issue. Microsoft needs to create a patch for ASAP.

Answer 3

Is the flawed KB5009543 that disables L2TP VPN connections going to be fixed?

Answer 4

• Certain IPSEC connections might fail
• New Windows KB5009543, KB5009566 updates break L2TP VPN connections

Answer 5

have you solve?

i do not know if is a problem about remote pc or my laptop,

pls i'm out of the system...