I am trying to connect to a Windows 8.1 PC via a VPN. I am using IPSEC and have what I believe to be the correct services running on the PC. I have also set up my router to port forward ports 500, 50, 51, 1701, 4500(tried for various reasons). Lastly, I have set up a connection on the client PC(also windows 8.1) using Layer 2 tunneling and a PSK. After all of this I am getting the following error: The L2TP connection attempt failed because the security layer could not negotiate compatible parameters with the remote computer

Any Ideas?

Hi

According to your description,please check VPN setting for your client PC.

Ensure your vpn configuration is right.

Then,check that Windows services on your device are configured as described below.

1.Press Win+R,type"services.msc",press Enter.

2.In the "Services" window,scroll down the list to "IKE and AuthIP IPsec Keying Modules".

3.Ensure the "Startup type" is set to be "Automatic" and the "Service status" is "Started".

4.Now back in the "Services" window, double click on "IPsec Policy Agent".
Repeat the same process as for the "IKE and AuthIP IPsec Keying Modules", ensuring the "Startup type" is set to be "Automatic" and the "Service status" is "Started".

Meanwhile,lets temporarily disable Windows firewall and security software.

Regards,