What does ubuntu use for a firewall?

[Bruce Marshall]

On Thursday 26 April 2007, John L Fjellstad wrote:
> > Installation of shorewall requires the removal of guarddog.. not sure if
> > guarddog is a firewall software or not. Never used it it was included
> > with my feisty install.
>
> Must have been included by a separate installation, because my Feisty
> upgrade didn't include guarddog, and I don't see guarddog in the
> dependency list of ubuntu-desktop

Not installed here either.