I have a Proxy server (ISA Server) running on a 2000 Server Platform. It's used for authenticating users for browsing on my network, but the users have to log on to the domain which uses a NT 4 Platform. I noticed that users are giving out their password for others to browse on their PC. This is congesting my network. Is there anything I can do to make sure that only one session for a user can run on the ISA server at any given time?
However, from a security standpoint you should also take non-technical steps to try to alleviate the "users sharing passwords" problem, because it is a huge breach of security on your network. It's a good step to figure out how to limit your users to a single connection, but the larger problem (to me, at least) is stopping your users from sharing their passwords in the first place. Depending on the current configuration of your account and password policies, I would begin mandating more frequent password changes and account lockouts to drive home the point.
This was first published in April 2004