securing Ubuntu and firewall

[Ted Treadwell]

--- "H.S." <hs.samix at gmail.com> wrote:

> John Richard Moser wrote:
> > you don't need a firewall unless you installed
> something nasty.  Ubuntu
> > doesn't open ports by default on the outside.
> 
> Can somebody else confirm this? I personally don't
> think that is true.

Ubuntu by default doesn't listen on any ports so no
connections should be made unless and until initiated
by the machine in question.

> When I checked using "iptables -nvL" command on my
> friend's computer,
> his INCOMING, FORWARD and OUTGOING policies were all
> ACCEPT. The system
> is relatively a new install of Ubuntu. So it appears
> all ports were
> actually left open since the installation.
> 

This indicates no packet filtering is happening, i.e.
no firewall, but the ports are still all closed.

> Moreover, I would rather have a firewall no matter
> if I have "nasty
> programs" (whatever that means) or not. It is just
> being cautious.
> 
> regards,
> ->HS
> 

I tend to agree.  I use iptables directly because I
wanted to learn how it works.  I used the tutorial at
http://www.faqs.org/docs/iptables/  Hope this helps.

-Ted