is the VPN server also DC, DNS and WINS? this may help, quoted from
http://www.howtonetworking.com/nameresolutionpnvpn.htm
Connection issues on DC, ISA, DNS and WINS server as VPN server
Symptom: You have a Windows 2000/2003 server is configured as VPN running
DNS, WINS, you may experience some connection issues. 1) the internal
computers can't ping the server by name; 2) if the server is a DC and Master
Browser, you may have a computer browsing issue; 3) you may receive Event
ID: 4319 - A duplicate name has been detected on the tcp network; 4) You may
receive error messages like "No Logon Servers Available to Service your
Logon Request" when you try to open file shares or map network drives to the
Routing and Remote Access server; 5) if the server is also a DC, you may not
be able to logon the domain; 6) if the server is also running ISA, you
cannot browse the Web from client computers on the local network, regardless
of whether the computers are configured to use Web Proxy or the Microsoft
Firewall Client. For example, "The page cannot be displayed" may appear in
the Web browser with a "cannot find server or DNS" error message.
Cause: When a VPN client connects to the VPN server, the server creates a
PPP adapter to communicate with the remote computer. The server may then
register the IP address of this PPP adapter in the DNS or the WINS database.
When the internal computers try to connect to the IP address of the PPP
adapter, them cannot reach the PPP adapter, then the connections fail.
--
For more and other information, go to
http://howtonetworking.com.
Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.
Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, Remote Access on
http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
