I am back again with my VPN problem.
I have Windows Server 2008 behind D-link DFL 1700 firewall. Server is setup as simple RRAS with VPN server.
Sometimes it works great, no problems, but most of the time VPN connects sucessfully, but after few minutes VPN begins with problems:
1.) first, after few minutes, all data transfer is lost, RDP disconnects and cannot connect back, file transfers are dropped, BUT pinging the VPN server still works!
2.) after another minute or so, also PING to VPN server drops, but on client side VPN tunnel still shows "Connected" state
3.) if I try to reconnect IMIDIATELLY, VPN dialing timeouts on "Verifying username and password" and drops with Error 806
4.) I need to WAIT at least 3-5 minutes for next sucessfull VPN dialup
5.) GOTO (1)
I am SURE that there is no problem on Client side, because I have 3 computers on client side, Windows 2003, 2008 and Vista and all have same problems. Also, all 3 client computers can connect to ANY other VPN server and I have lots of them all arround the world for remote management.
So, the problem is DEFINITELLY on server-side (Windows 2003 Server R2 with SP2):
- either some weird DFL-1700 function, which begins blocking VPN after some time
- either some Windows Server 2003 VPN defect
- either something AD related (VPN server is NOT DC, but is a member of domain; VPN clients are domain users)