Always On VPN Error 13801

Troubleshooting Always On VPN Error 691 and 812 – Part 2

Certificate configuration is crucial for Always On VPN deployments. I described some specific certificates requirements for IKEv2 in this previous post. Following this guidance, administrators should have no issues with IKEv2 Always On VPN connections. However, it is always possible to encounter an error if any of these certificates are missing or misconfigured.

Error 13801

One of the most common errors related to IKEv2 and certificates is 13801. When an Always On VPN connection using IKEv2 fails, the Windows Application event log will record an event ID 20227 from the RasClient source. The error message states the following:

“The user [username] dialed a connection named [connection name] which has failed. The error code returned on failure is 13801”.

IKE Authentication Credentials are Unacceptable

Error 13801 translates to ERROR_IPSEC_IKE_AUTH_FAIL, indicating an authentication failure related to IPsec. The problem can be on the device, the VPN server, or an issue with the VPN server configuration.

Certificate Chain

A 13801 error will occur if the client does not trust the certificate installed on the VPN server. Ensure the client has all the necessary root and intermediate certification authority (CA) certificates installed in their respective certificate stores.

VPN Server Certificate

A 13801 error can also occur if the VPN server does not have a properly configured server certificate. Ensure the VPN server has a valid certificate issued by the organization’s internal PKI that includes both the Server Authentication (OID 1.3.6.1.5.5.7.3.1) and IP security IKE intermediate (OID 1.3.6.1.5.5.8.2.2) EKUs. The subject name must match the public fully qualified domain name (FQDN) used by VPN clients to connect to the VPN server (not the server’s NetBIOS name). Again, ensure the certificate is valid (not expired), trusted, not revoked, and all necessary root and intermediate CA certificates are installed in their respective certificate stores.

Certificate Revocation

An expired Certificate Revocation List (CRL) can also result in a 13801 error. Open the Enterprise PKI console (pkiview.msc) on an issuing CA and review the status of all CRLs. If any are expired, resolve any issues preventing the CRL from publishing successfully, then issue a new CRL by running certutil.exe -crl on the issuing CA server.

RRAS Configuration

Another cause of the 13801 error for the device tunnel is a misconfigured Routing and Remote Access Service (RRAS) VPN server. An error 13801 can happen if the administrator incorrectly defines a trusted root CA using Set-VpnAuthProtocol. Ensure that the root certificate thumbprint matches exactly the root CA server’s thumbprint used to issue certificates to VPN devices and the VPN server.

Get-VpnAuthProtocol

Root CA Certificate Thumbprint

Resolution

Ensure that devices and VPN servers have correctly configured certificates installed. If the root CA certificate is assigned incorrectly on the VPN server, follow the guidelines detailed here to update the configuration.

Additional Information

Microsoft Windows Always On VPN Error 13806

Microsoft Windows Always On VPN Certificate Requirements for IKEv2

Microsoft Windows Always On VPN IPsec Root Certificate Configuration Issue

Microsoft Windows Always On VPN IKEv2 Policy Mismatch Error

Microsoft Windows Always On VPN IKEv2 Security Configuration

Microsoft Windows Always On VPN IKEv2 Fragmentation

Microsoft Windows Always On VPN IKEv2 Load Balancing and NAT

Microsoft Windows Always On VPN IKEv2 Features and Limitations

Always On VPN Windows 11 Issues with Intune

Always On VPN RasMan Errors in Windows 10 1903

Since the introduction of Windows 11, there have been numerous reports of issues with Always On VPN when deployed using Microsoft Endpoint Manager/Intune. Specifically, administrators have been reporting that Always On VPN profiles are being deleted, then later reappearing. Obviously, this is highly disruptive to users in the field.

Update January 25, 2022: Microsoft has released a fix for the issues described in this article. It is included with KB5008353 (build 22000.469).

Causes

According to Microsoft, there are several causes for deleted VPN profiles.

Changes to an Existing Profile

Missing Always On VPN profiles commonly occurs when updating settings for an existing VPN profile applied to Windows 11 endpoints. In this scenario, the VPN profile is deleted but not immediately replaced. Synchronize the device with Microsoft Endpoint Manager/Intune once more to return the VPN profile.

Multiple Profiles

Issues with Always On VPN profiles may also occur if two new VPN profiles are applied to the endpoint simultaneously.

Remove and Replace

Removing and replacing an Always On VPN profile at the same time will also result in connectivity issues.

Reference: https://docs.microsoft.com/en-us/mem/intune/configuration/vpn-settings-configure

Workaround

There is no known workaround for these issues at this time. Microsoft is aware of the problem and is working on a fix, and until then, rolling out Windows 11 with Always On VPN should be avoided.

Additional Issues

There have been reports of other known issues with Windows 11 and Always On VPN. For instance, my PowerShell script that removes an Always On VPN connection doesn’t work with Windows 11. I’m working to resolve that issue as we speak.

Are you experiencing any issues with Always On VPN on Windows 11? Please share them in the comments below!