look for a firewall

[Tom Bell]

I have found IQFireWall to be an excellent firewall and it works with
Kubuntu 10.04 AMD64 as well as i386.
http://sourceforge.net/projects/ipfire-wall/

You just need to follow the installation instructions to add the
required files before installing the firewall.
If you need something really simple, I don't know what that would be.
Good luck!

Tom
-- 
 Quis custodiet ipsos custodes?  -- Decimus Iunius Iuvenalis (Juvenal),
Roman Poet, late 1st, early 2nd century AD
("Who will protect us from the protectors?")