As you might have guessed from previous posts, I’m currently in the process of implementing a single-sign-on scenario within our network. Or, at least, I’m trying to have at least one single username/password combo for all internal services. Authentication is therefore realized against an Active Directory, based on a Microsoft Windows 2003 Server.
For integration of Bugzilla into the Active Directory, see this link (Update: Link is broken, for an archived version, use this link, thanks to the commenter!).