We are going to let one of our sysadmins go in a few weeks. He has access to our entire infrastructure, so we'll have to reset the passwords on everything. This is going to be really time consuming though, with the number of servers and devices out there we would have to reset. A few things are tied into Windows domains so that's easy enough, but problematic depending on whether any services run as that user.
Is there any way to easily revoke access to everything for that user? I guess I'm asking for cross platform single sign-on...maybe RADIUS can do this? Or is there a turnkey solution out there like RSA SecureID? What have you guys used?