I have been having a strange issue with a L2TP VPN connection using certificates to a 2008 R2 server. Some systems on some networks cannot connect successfully. Nothing is logged on the Server 2008 R2 box. I see the traffic being passed from our firewall to the box, but it does not complete the tunnel setup.
For example, I have one laptop that I cannot connect from my house, but can from other locations. I have a second laptop that connect from my house with no problems. I have seen this issue on at least 5 computers. Until I can resolve this,
I have to keep my 2003 VPN server running so that users have a fall back VPN to connect to.
Error 789: The L2TP connection attempt failed because the security layer encountered a proccessing error during the initial negotiation with the remote computer