Virtual Private Networking
Virtual Private Networking |
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The following tools, which enable you to gather additional information about the source of your VPN problem, are included with Windows 2000.
When a demand-dial interface fails to make a connection, the interface is left in an unreachable state. Right-click in the interface, and then select Unreachability reason to obtain more information about why the interface was unable to connect.
On the Event Logging tab in the properties of a VPN server, there are four levels of logging. Select Log the maximum amount of information, and then try the connection again. After the connection fails, check the system event log for events logged during the connection process. After you are done viewing remote access events, select the Log errors and warnings option on the Event logging tab to conserve system resources.
Tracing records the sequence of programming functions called during a process to a file. Enable tracing for remote access and VPN components as described in "Routing and Remote Access Service" in this book, and then try the connection again. After you have viewed the traced information, reset the tracing settings back to their default values to conserve system resources.
Tracing information can be complex and very detailed. Most of the time this information is useful only to Microsoft support professionals or to network administrators who are very experienced with the Routing and Remote Access service. Tracing information can be saved as files and sent to Microsoft support for analysis.
Use Network Monitor, a packet capture and analysis tool, to view the traffic sent between a VPN server and VPN client during the VPN connection process and during data transfer. You cannot interpret the encrypted portions of VPN traffic with Network Monitor.
The proper interpretation of the remote access and VPN traffic with Network Monitor requires an in-depth understanding of PPP, PPTP, IPSec, and other protocols. For more information about PPP, see "Remote Access Server" in this book. Network Monitor captures can be saved as files and sent to Microsoft support for analysis.