Determine Distro without logging in.
I have a set of boxes that are all versions of Centos, Debian, Red Hat and maybe a couple other distros and have been tasked with determining and documenting which box is which OS. However, I cannot login to any of the boxes for privacy reasons or turn them off. Every box has no GUI (console only) so the most I can access is the login screen.
I know it may be impossible, but is there any telltale signs to look for in order to determine what distro is running from just a console login?
Any help would be appreciated.