We have a 2008 R2 server, acting as domain controller, at site #1. IP Address - 192.168.120.50.
At site 2, we have a Vista Business workstation, (workgroup) IP address - 192.168.0.x.
Vista business workstation uses Cisco QuickVPN to connect to site 1. (This works, wkstn can ping server by IP address)
Vista wkstn cannot establish RDP session or access any shares (administrative or otherwise) on 2008 server using Administrator credentials
At site 3 we have a Win7 Ultimate workstation that uses Cisco QuickVPN to connect to site 1 and can achieve file access and RDP sessions with the same adminstrator credentials that do not work for Vista Business workstation.
I assumed an authentication protocol mismatch. Accordingly I adjusted security policy on vista wkstn - no help. (Administrative tools, Local Security Policy, Local Policy, Security Options, Network Security LanManager Authentication Level, Send LM
& NTLM, use NTLMv2 session security if negotiated.)
I can't find anything in the event logs on the server nor the vista wkstn that indicate failed authentication.
I assume I'm missing something straightforward and simple, but am pulling my hair out.