Because of the different components and processes involved, troubleshooting a VPN enforcement deployment can be a difficult task. This section describes the troubleshooting tools that are provided with Windows Server 2008 and Windows Vista and how to troubleshoot VPN enforcement starting from the NAP client.
Microsoft provides the following tools to troubleshoot VPN enforcement:
TCP/IP troubleshooting tools
NAP client event logging
NPS event logging
NPS authentication and accounting logging
Netsh NAP tracing
VPN server event logging
Network Monitor 3.1
The Ipconfig tool displays the state of a NAP client. At a command prompt on a NAP client, run the ipconfig /all command. ...