I use theL2TP/IPSecVPNusingPre-Shareke mechanismonwindow2008R2: After installing theVPNRoutingand RemoteAccess Services.I proceeded totest -ThetestontheVPNIP10.57.55.2successfully -Thetestontheinternet, the IPNATerror. . Thanksyouhelp me with. Port1701open on thefirewall, 500, 4500, 1723. ..all portsthroughNATandak. -TheVNPserverconfigurationsettingsI justsetup andPre-Shareke only. I do not knowwhenthatNAT, there shouldVPNrequestdiffers fromits realIPVPNto10.57.55.2not? .HIC   Ithankyou.

Hi, Have you set the port mapping on the firewall? On the NAT devices, you need to specific inbound port numbers to the internal IP addresses. Such as, 1701 port forward to 10.57.55.2 (VPN server). VPN and NAT Design http://technet.microsoft.com/en-us/library/ff687823(v=ws.10).aspx Address and Port Mapping for VPN Traffic http://technet.microsoft.com/en-us/library/cc958044.aspx Best Regards, AidenAiden Cao TechNet Community Support

Hi, Have you set the port mapping on the firewall? On the NAT devices, you need to specific inbound port numbers to the internal IP addresses. Such as, 1701 port forward to 10.57.55.2 (VPN server). VPN and NAT Design http://technet.microsoft.com/en-us/library/ff687823(v=ws.10).aspx Address and Port Mapping for VPN Traffic http://technet.microsoft.com/en-us/library/cc958044.aspx Best Regards, AidenAiden Cao TechNet Community Support