In all of the problems discussed in the previous installments of this article, the client is able to contact the VPN server but is unable to negotiate a VPN connection because of configuration settings that do not meet the server’s criteria. Sometimes, you will see the Error 769 message (The specified destination is not reachable).
There can be three causes of this error:
- The VPN server may be offline. You should attempt to ping the server to ascertain whether it is online.
- You may have entered the wrong server name or IP address for the VPN server in the client configuration properties. You should recheck the entry and ensure you have the proper name or IP address entered.
- There may be a name resolution problem if you are trying to connect by server name. You should try connecting by IP address instead of server name. If you can ping the server by IP address but not by name, this means that either the server does not have a registered domain name, or the DNS server on the network is down or not functioning correctly.
Note that if the VPN server has a dial-up connection to the Internet, it is likely that the ISP will assign it a different IP address each time an Internet connection is established. You will not be able to connect by IP address unless you know the IP address currently assigned to the server. More commonly, a VPN server will have a permanent (static) address and a dedicated full-time Internet connection.
Problems after connecting
If it appears that the VPN has connected successfully, but you are unable to access resources on the server or LAN, you can check the status of the connection in several ways.
The Vista client will have an icon in the system tray for each remote access connection. Right-click the icon and click Status. You will see a status box appear. In the Activity section, note changes in the number of bytes sent and received to confirm that traffic is going across the VPN connection.
At the command prompt, run netstat. This will show a list of active connections. In the Foreign Address column, you can recognize VPN connections by the appearance of the type of tunneling protocol (PPTP, L2TP, or SSTP) following the foreign address.