We have a single domain running across 4 sites connected by a relatively slow VPN. All 4 sites have a Domain Controller, with the primary domain controller (DC1) in the head office. All clients run Windows XP SP2.
Some, but not all, users at one of the remote sites are reporting slow response from Windows Explorer when browsing thei computers. Having eliminated a number of other issues, I have examined the security logs on the remote site (DC2) and head office (DC1) domain controllers and noticed that the users who are having problems appear to be authenticating to both their local domain controller (DC2) and the head office domain controller (DC1) The delay in the WAN link may explain the problem. Active Directory Sites and Services has been configured (correctly I think)
Any suggestions on how I can encourage clients to authenticate only to their local domain controller?