Hello, I've set up a VPN on my Server 2008 machine that's behind a NAT router with 1 NIC. I can connect to the VPN (although I'm not entirely convinced I set everything up perfectly), however I get hundreds of these errors every time the RRAS service starts (or the machine reboots): ----------- Log Name: System Source: RemoteAccess Date: 6/8/2011 11:39:30 AM Event ID: 20171 Task Category: None Level: Warning Keywords: Classic User: N/A Computer: SERVER Description: Failed to apply IP Security on port VPN2-96 because of error: A certificate could not be found. Connections that use the L2TP protocol over IPSec require the installation of a machine certificate, also known as a computer certificate.. No calls will be accepted to this port. ------------ Any help would be great! I'm pretty new at this - so take it a bit easy on me :-) Thanks, - Brian

Hi Brian, Thank you for your post. The error is caused by RRAS service check the certificate that need to use for L2TP/IPSec VPN. If you want to use L2TP/IPSec VPN, please install certificate in your domain refer to this article. If you do not use L2TP/IPSec VPN, please try to disabled L2TP/IPSec port in RRAS console--ports--right click properties--WAN Miniport(L2TP)--Set Maximum ports to 0 value. Another way to resolve this issue is configure the remote access service to start manually instead of automatically, please refer to KB306193. If there are more inquiries on this issue, please feel free to let us know.Regards, Rick Tan