VPN - Network - Domain Controller

Ok..I'm running two different types of VPN's one is a regular VPN (PPTP) and
the other is an SSL VPN... I'm having the same problem with both which leads
me to believe that it might not be a VPN issue but instead it can be a
network issue.



I can connect to my network using both VPN's and I'm able to sync to my
exchange server but when I try to open a map share drive I get the following
error "An error occurred while connecting F: to \\servername\sharename
Microsoft Windows Network: The local device name is already in use. This
connection has not been restored.



And when I try to map a drive I get the following error: "The user name you
typed is the same as the user name you logged in with. That user name has
already been tried. A domain controller cannot be found to verify that user
name".



Keep in mind that this does not happen all the time but it does happen with
all users including me and I have admin rights.

Does anyone have any idea why I'm getting those error messages and tell me
how to fixed them?

Thanks