Working with a SonicWall TZ170 and four machines configured to accept remote desktop connections through the SonicWall TZ 170. All four VPN connections have worked fine for several months. The machines are three XP workstations and (1) Windows 2008 server R2.
Last week the connections stopped working. So far we have the following:
All remote users can successfully connect to the Sonicwall.
If they attempt to use RDP to connect to their machine the connection fails with the usual MS rdp error about cannot connect, check the machine has remote access enabled etc etc.
Within the premises, rdp to each of the machines works. It is only when the RDP connection is attempted through the firewall that it fails.
In the process of troubleshooting I have:
Turned off Windows firewall
Turned off Vipre Anti-virus business (which does not have a firewall)
I can ping each machine from a remote machine... but have some odd behavior...
When I ping, I get (1) reply... then the next (3) time out. Any subsequent ping attempts receive (4) time outs.
If I ping another address, I get the identical behavior... one reply then time out and subsequent attempts get (4) time outs.
The "Terminal Services" services (named Remote Desktop on the server) on all four machines are running.
Baffled. Suggestions welcome.