DUO-Watchguard problem on L2TP VPN

Good day,

I have a Watchguard firewall with SSL and L2TP VPN configured on it.
The SSL VPN authentication works perfectly well with DUO, but the L2TP VPN fails.
When I connect the L2TP VPN, I even get the push notification from DUO and Watchguard shows me the log that the authentication has been successful, but the VPN does not connect.

I showed the configuration to Watchguard and at the end, their support told me these exact words"The trouble you are experiencing with Duo MFA integrated with L2TP VPN, is a known issue with the vendor. There is nothing that can be done on the Firebox to make this configuration work, the configuration is not supported."

So What should we do now? Is something being done or anything in progress to solve this issue?

Thank you.


I’m not sure what issue they’re talking about. We usually see Watchguard IKEv2 or SSL VPN questions here. There was an issue with the Authentication Proxy and MS-CHAPv2, but it’s been corrected and confirmed by other Watchguard users in this community.

Please contact Duo Support to open a case, so they can get more information about your issue.

Thank you for your reply.

Will do.