How can I limit "users" to secure shell "logging on" to only 1 remote address at a time?
Object: Prevent users(cooperative students) from copying/pasting work from one to another.

How can I limit "users" to secure shell "logging on" to only 1 remote address at a time? Object: Prevent users(cooperative students) from copying/pasting work from one to another.
I think that's a flawed method. Like what if they're behind the same IP address?.. BTW, I think you're overlooking email, portable media, scanners, photocopiers, writing, cams. Closing one hole is a good way to force them to open up another can of ingenuity.

IMNSHO user separation and DAC permissions are nothing compared to good old reading & comparing results.

I need to have this setting in ssh, bash, or whatever. Let me explain:

I teach C++ and Java in a public school here in the States. All 25 of my computer hard drives are unplugged(contains Windows XP), by my design. This keeps them on task in a controlled Linux environment. I also block the Internet from their use. A libability issue, CYA. There is no need for Internet use in my classroom curriculum. Besides, I just want them to use Linux!

I have created my own version of a Knoppix based Live CD (called No-Games_Knoppix.iso). We use it entirely in my classroom. Each student uses this Live Cd and "secure shells" onto my local (my classroom) Fedora C4 box, inside the same school system(DHCP). I'm the admin for this box. Students are their own "user" and "group" on this Fedora box with no read or write ability to any of the other users or groups. All 25 classroom computers are on the same school DHCP system in my classroom. I have no school system admin authority beyond what I have described here. The school system is entirely Microsoft.

Problem: Is there a way to limit, by script or other means, users from logging into more than one(1)user account at a time? ... Example: Two students cooperate and both of them login to their own accounts, on the same X-window(screen). They can copy and paste one to the other. One student can do one piece of work and the other another piece. What if more than two or many cooperate in this scheme?

Needs: By virtue of this problem, I need a solution that I can "burn" onto my own "No-Games iso" or a perhaps a setting I can use on the Fedora box.

Thanks to all who have read this, have a great day!

Would have been more efficient posting detail up front, but OK. I prolly am thick since I still don't dig what provides their shared whatever session, but OK. Maybe look at /etc/security/limits.conf, like "maxlogins". Note this probably isn't "1" but a bit more. You'll have to experiment.

A repost if your will:

How can I limit any user, and there can be many users logged in at one time, to only one shell login per IP address? All users are on a local DHCP assigned IP addressing.