[PLUG] Ethernet patch cable alarm...

[plugng3 at martinconsulting.com]

> Wouldn't it suffice, and perhaps be easier, to "cap" the end of the 
> cable in such as way as to make non-un-pluggable without some sort of
"key"?

If they're not *too* motivated, you can cut the narrow part of the release
tab off of the cable head.  That's the part that sticks out when a cable is
plugged in, that you press on to release the cable.  Without that, you have
to use a small tool (small screwdriver, nail file, etc.) to reach the
remaining part of the release tab.  It's more "security theater" than
security, but it's quick, cheap, and might meet your needs.  If your cables
have non-snag boots on them, it'll be even less obvious what you've done.

> Out of curiosity, how do I program a Linux server to beep when a patch
> cable is disconnected from it?

I don't know, but at least some distros show an entry in the syslog when an
Ethernet cable is plugged or unplugged.  Linux has a configurable hardware
event notification system.  Someone on the list probably already knows a lot
about it.  I believe this is the mechanism that also responds to CDs being
loaded, USB devices being plugged and unplugged, etc.  If the external
server OS is trusted, you could probably use this to just have it turn off
the network interface in response to an unplug until someone (you) comes and
fixes it.  One or two cycles of that and people will learn that moving the
network cable breaks the server and doesn't get them what they want. 

The bigger issue is "why are they doing this".   If it's porn, downloading
pirated movies, etc.,  that's a firing offense at most companies.  A memo
from the manager reminding them of that keeps you out of the policeman role.
If it's a legitimate work-related need, then you need to find a way to help
them meet their job needs without circumventing the content filter.
Technology is often not the right solution to people problems.