Windows 10: The L2TP connection attempt failed error VPN

Hi,I just recently got instructions from my company to install VPN, everything worked fine for few days and now i got this message:The L2TP connection attempt failed because the security layer encountered a processing error during the initial negotiations with the remote computer.I have windows 11 with all updates up to this date 20.03.2023.Also i tried many options CHAP2 turned on, LCP extended stuff enabled, uninstalled drivers from device manager and installed again. I am simply out of options.Can you helpthe issue?System information:-----------------------------------------------OS Nam

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VPN - "The L2TP connection attempt failed because security policy for the connection was not found".

Connecting Windows 10 VPN to Draytek routers on numerous sites all returns the same error. Sometimes a reboot works, sometimes it doesn't. Have followed all steps in the similar message (The L2TP connection attempt failed because the security layer encountered a processing error during the initial negotiations with the remote computer), but this error of mine is "security policy not found". Where is the security policy and why does it have a problem finding it sometimes??

 

Error: 788, when connecting to L2TP VPN

Hi there, recently I got this error when connecting to "L2TP/IPSec with certificate" VPN. I'm not sure what cause this.

I have already follow some of this steps with no luck :

• Adding AssumeUDPEncapsulationContextOnSendRule
• Restarting both IKE and IPSec services
• Allowing both CHAP and MS-CHAP v2
• Reset network connection
• Connect to different provider
• Re-adding VPN settings

There also little bit information can be found in the event viewer :

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx has started dialing a VPN connection using a per-user connection profile named yes. The connection settings are:

Dial-in User = *\

VpnStrategy = L2TP

DataEncryption = Requested

PrerequisiteEntry =

AutoLogon = No

UseRasCredentials = Yes

Authentication Type = PAP

Ipv4DefaultGateway = Yes

Ipv4AddressAssignment = By Server

Ipv4DNSServerAssignment = By Server

Ipv6DefaultGateway = Yes

Ipv6AddressAssignment = By Server

Ipv6DNSServerAssignment = By Server

IpDnsFlags =

IpNBTEnabled = Yes

UseFlags = Private Connection

ConnectOnWinlogon = No

IPsec authentication for L2TP = Machine certificate.

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx is trying to establish a link to the Remote Access Server for the connection named yes using the following device:

Server address/Phone Number = xxx.xxx.xxx.xxx

Device = WAN Miniport (L2TP)

Port = VPN3-1

MediaType = VPN.

CoId={AEE0E2A8-34DF-41BB-B5F0-0458EFD41751}: The user xxx\xxx dialed a connection named yes which has failed. The error code returned on failure is 788.

***Original title: VPN Error 788***

 

L2TP VPN on Lumia 950 giving error code 812

Hello,

I recently purchased a Lumia 950 (AT&T running Windows 10 Mobile build 10.0.10586.0.

When I configure my work IPSec L2TP VPN connection on my phone and then attempt to connect, it attempts to connect, then fails displaying the error:

The VPN connection failed with error code 812.

This seems to happen after the credentials are accepted.

During the connection attempt on the phone, the status display progresses as follows:

• Connecting to <address of my VPN server>
• Verifying your credentials
• Connecting to <address of my VPN server>
• The VPN connection failed with error code 812.

When I look at the logs of my VPN server, a connection is actually established successfully by the client, then immediately terminated.

I'm not positive who is terminating the connection on who (client or server).

VPN Settings configured on the Lumia 950 are as follows:

Connection name: My Work

Server name or address: <address of my VPN server>

VPN Type: L2TP/IPsec with pre-shared key

Pre-shared key: <pre-shared key that is configured on my VPN server & working on other devices>

Type of sign-in info: User name and password

I have typed the username & password in again multiple times to confirm it is correct. It is.

Furthermore, I have a Lumia 925 running Windows Phone 8.1. It connects perfectly using these same settings.

It seems something changed in Windows 10 Mobile that caused this VPN connection to stop working.

Do you have any suggestions on how I might be able to get this resolved?

I really need the VPN to be working.

Thanks!

-

Doug Mortensen

Impala Networks