%global_entities; ]> &author.jht; The Microsoft Windows operating system has a number of features that impose specific challenges for interoperability with operaing system on which Samba is implemented. This chapter deals explicitly with the mechanisms Samba-3 (version 3.0.8 and later) has to overcome one of the key challenges in the integration of Samba servers into an MS Windows networking environment. This chapter deals with IDentity MAPping (IDMAP) of Windows Security IDentifiers (SIDs) to UNIX UIDs and GIDs. So that this area is covered sufficiently, eash possible Samba deployment type will be discussed. This is followed by an overview of how the IDMAP facility may be implemented. The IDMAP facility is usually of concern only where more than one Samba server or Samba network client is installed in the one Domain. Where there is a single Samba server do not be too concerned regarding the IDMAP infrastructure - the default behavior of Samba is nearly always sufficient. There are four (4) basic server deployment types, as documented in the chapter on Server Types and Security Modes.