control of internet access

[Kai Wüstermann]

Moin!

We are a primary school with children up the age of 10. So we need to
control the Internet access in edubuntu for the children.

We want to...

... switch off the Internet for all the thin clients

... log the sites and pages a user retrieves

... use a blacklist for the children's Internet access

... switch on the Internet access (It would be nice to do this for
special user groups or classrooms)

To switch on/off the Internet access seems to be easy if I add/delete
the default route. But I also switch off the Internet access for the
server itself so it can't do jobs like fetching mails, updates or time.

For logging an using blacklist I could use squid but how do I avoid
firefox accessing directly to the Internet.

Every suggestion is welcomed.

Thank you
Kai Wüstermann