View Full Version : [ubuntu] [SOLVED] [firewall] use it or not? which?

May 28th, 2008, 10:14 PM

I wonder whether or not I should use a firewall on my system (laptop/desktop), at a home wlan and lan at school, respectively.
I use torrent and emule a lot, take care of bank transactions online,
plus regular emailing and IMs. Before I switched to Ubuntu, I've been using
Norton on Windows, which was a failure in many cases. But I don't know if it'd be absolutely necessary to run a firewall on Ubuntu, because it's supposed to be a lot better in security aspect.

If I do have to use one, is firestarter good enough?
I'm new to these network security issues and have really limited knowledge about networking. Where should I start if I do need to?
Thank you.

May 28th, 2008, 10:22 PM
Rightly or wrongly, I run no firewall or virus protection on my Kubuntu boxes. I rely on the firewall in my router.

18 months down the line I've had ZERO issues.....

The wife's XP box has been rebuilt twice in the same time frame!

May 28th, 2008, 11:10 PM
Regardless of necessity, would it hurt to install one? Its better to have and not need, then need and not have.

(why are my coffee beans all goofy?)

May 28th, 2008, 11:13 PM
Why bother

May 28th, 2008, 11:28 PM
It does not require a large amount of time to install and configure a firewall, so there is no harm in doing so.

May 29th, 2008, 12:12 AM

because i've experienced weird network debugging before, and firewalls, in peaceful times, always give me headaches...

so be it difficult to install or not, i'd rather do it when it's absolutely necessary.

so please give an idea how i am gonna run into cumbersome authorization for sth that's really harmless and stuff...


Dr Small
May 29th, 2008, 01:06 AM
Having a firewall on each system that is behind a router with a built in firewall is nonsense. I did it for several months, and then found out that every little application that the other network computers need to connect to me (Samba, HTTP, SSH, Bzflag, etc), I had to open a port.

It is much simpler now that I do not have a firewall, and just let my router handle all incoming requests from the internet.

By the way, Firestarter is not a firewall. It simply manages the firewall (iptables) in a unique graphical way. It in itself is not a firewall.

Dr Small

May 29th, 2008, 01:10 AM
Why bother

It's a matter of personal choice. If you're not at risk, then there's no need. A bigger danger exists if you think you're not at risk when you are. The only truly secure computer is one which is not connected to anything else.

May 29th, 2008, 10:52 AM
(1) do you run any services on your computer? If no, then you don't need a firewall

(2) if you run services, do you use the computer only at home (behind a router) or in firewalled networks? --> If any is yes, then you don't need a firewall

(3) if you run services and if you do run your computer in "untrusted" networks then you might need a firewall

May 29th, 2008, 10:54 AM
I use Firestarter myself and I don't see a point why I shouldn't. It blocks unnecessary ports, etc. If you're on Unix or Linux it doesn't make you 100 percent safe. That's what I think.

May 29th, 2008, 10:55 AM
It's a matter of personal choice. If you're not at risk, then there's no need. A bigger danger exists if you think you're not at risk when you are. The only truly secure computer is one which is not connected to anything else.

Oh, and truly secure computer is the one that is powered off. :)

May 29th, 2008, 11:09 AM
and in your bank's vault :)

May 29th, 2008, 11:17 PM
Ubuntu's firewall is known as IpTables. Its possible to manually edit the Iptables by hand, however for beginners its often easy if a program does it automatically. Firestarter is such a program that modifies the IPtables in a very easy way. If you are on Kubuntu, Guarddog is the Firestarter equivalent. (I actually prefer Guarddog to Firestarter but that is my personal opinion).

You only really need a firewall if you are running open ports or running a server that is transparent to the outside world. The Iptables are able to block by port number, IP address, access time, etc. They are actually quite powerful. If you are not running any services that are visible to the outside world, then you really don't need a firewall, since no service or daemon is listening for outside connections. I suppose if you were really paranoid, in addition to blocking incoming ports, you could block outgoing ports in addition, however this would take a lot of trial and error since many outgoing ports are probably used frequently on your computer (sudo netstat -an <---Will show you what I mean).

Evaluate your needs. If you think you need a firewall, go with Firestarter initially. Its fairly easy to understand.

May 29th, 2008, 11:22 PM
thx guys and especially you kevdog.
That explained a lot!