Domain Authentication for LinuxI've updated the instructions here to support RHEL 6. I've streamlined things a bit, too, so I'd head over to this page to get the latest on setting up AD authentication for a Linux server. There are a lot of how-tos surrounding the integration of authentication and authorization in Linux through Active Directory domains. I've found a variety of them helpful, and I've found more to be confusing, rather than helpful. Here I'm hoping to put together a start-to-finish process for using your domain to authenticate and authorize users on your linux box. These instructions are written for Red Hat Enterprise Linux v5 (RHEL from now on). That means the file locations should be the same for CENTOS distros (which I highly recommend as a server OS), but that they might move around a bit for others.
A very small bit of background: this system uses winbind and smb to connect to the domain to authenticate users. Kerberos is used to join the system to the domain. The benefit of this system is that it's secure and it's pretty easy to configure. Coupled with PAM (Pluggable Authentication Modules), it's quite flexible, and it's really pretty cool functionality.