problem connecting a VPN server with L2TP/IPSEC security

Question

I just deployed a VPN server under Windows server 2019. My problem is this message during the connection: the l2tp connection attempt failed because the security layer encountered an error.

This test was done on the server itself locally, whereas with the connection in PPTP mode it works without any problem.

I would like to have your opinion please, because it is the first time that I do it with Windows. Usually I do it with Pfsense.

The machine is installed on hyper-v.

Thanks in advance!
Greeting.

Answer 1

@kader kader

Please confirm if the steps taken so far from you are the ones below:

-VPN Properties >>>>>>>>> Routing and Remote Access>>>>>>>>>Allow custom IPSec policy for L2TP/IKEv2 connection
-IPv4 tab >>>>>>>>> Enable IPv4 forwarding >>>>>>>>>Static address pool
-NAT tab >>>>>>>>> New interface >>>>>>>>> Public interface connected to Internet >>>>>>>>>Enable NAT on this interface
-Port tab >>>>>>>>> VPN Server(L2TP/IPSec on this server)
-Change IP address to 127.0.0.1
-Restart required
-Firewall settings configuration >>>>>> Inbound/outbound rules (allow Routing and remote access) >> Allow the connection
-VPN user profile set up (Allow the user connection)
-Recall to share the PSK(Preshared KEY with all users)

Looking forward to your feedback,

Cheers,

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Answer 2

Hi @kader kader

I am hoping you were able to get this working as intended. Please let me know if anything else is required.

Best Regards,

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Answer 3

for the moment I am doing the tests because it works well with windows server 2022 with the latest updates, on windows 10 it also works well with the latest updates but not with windows 2019 the problem still arises

Answer 4

the problem came from PFSENS. Thanks for your help.