Experimental exam mode (network blocking) in Debian Edu/Squeeze

[Petter Reinholdtsen <pere@hungry.com>]

Hi.  I just uploaded a new version of debian-edu-config activating an
experimental exam mode.  The idea is to block network traffic from
machines involved in the exam from reaching Internet, and limit
traffic to the local network(s) only.  This is done using iptables,
and the script debian-edu-update-netblock, written by me a long time
ago.  I just updated it to work on LTSP clients, where the initial
approach would fail when it pulled down the network from underneath
the root file system. :)

The idea is that computers used during exam will be configured to not
reach Internet, and all traffic will be routed through the HTTP proxy
where exam specific rules can be added.

To test it, add the host in question to the netgroup netblock-hosts
and wait 5 minutes.  If some users should be able to reach the
Internet also on machines with network blocking active, the users can
be added to the file group nonetblk to make this happen.

Give it a go and see if you believe this approach is useful or not,
and post your experiences here.  If not, we can pull it out again
before the release. :)

-- 
Happy hacking
Petter Reinholdtsen