Windows 10: VPN L2TP error code 809

Hello I need help.

my env: win 10 1909 build 18363.719, L2TP with preshared key

After I used CC cleaner my L2TP VPN stop working. Before was working fine and nothing changed on network or VPN server. Also on other devices works fine.
I try to kind of debug my situation and I figured out that my PC can communicate with server because I can see network communication in wireshark


wiresharK:





But the connection is not established successfully and i don't no why. I tried to set the register value AssumeUDPEncapsulationContextOnSendRule but without any change. Also turn off any Xbox network services


regedit:






VPN security setting:




event viewer:




Thank you for any advice

:)

 

809 Error in L2TP VPN

Hi Keshka,



Thank you for writing to Microsoft Community Forums.



We understand your concern as you are receiving an 809 error in Event Viewer. Ideally the issue should have fixed after you recreated the connection.



Let me point you in the right direction, where you would get the appropriate help for this issue. I would suggest you to post your query in
TechNet forums,
where we have experts and support professionals who are well equipped with the knowledge on L2TP VPN to assist you with the appropriate troubleshooting steps.



Aditya Roy

Microsoft Community – Moderator

 

809 Error in L2TP VPN

What the heck happened? Running Windows 19028VB_release.191115-1325. I created a VPN connection about two weeks ago and entered the reg key per:

reg add HKLM\SYSTEM\CurrentControlSet\Services\PolicyAgent /v AssumeUDPEncapsulationContextOnSendRule /t REG_DWORD /d 0x2 /f
All was working and it just took about 2-3 seconds to connect. This afternoon, forget it! I have checked all settings ...even deleted and recreated the connection. Nothing but the 809 error in the Event Viewer.
I NEED this in order to work. HELP!

Keshka

***Original Title: L2TP VPN ....WAS working this morning. What happened?***

 

IPSec VPN eror 809 after Windows 10 upgrade

I found that a windows 10 service blocks L2TP/IPSEC VPN access.

If you go to services.msc

Find "Xbox Live Networking Services" and disable that service.

After I did that the VPN worked for me.

I have tried everything from adjusting firewall rules to adding the registry entry to no avail with Error 809.