Firewall

[Tristan Wibberley]

Does anybody have a recommendation on a firewall in ubuntu (main,
universe, or multiverse) that is active before interfaces are brought
up, and after interfaces are taken down (using ifup/down). I'm looking
for one that's pretty easy to configure. It would be nice if it had a
gnome notification tray icon or panel applet to notify when it caught
something.

I'm currently using firestarter, but you have to start it manually (and
its configuration is limited).

Thanks.