The short answer to that is that you start of by telling it that every port
is blocked. Then you can say open this and that. You can do it the other way
around as well all open and block this looong list. (Guess which is handier
to use?)
You have a good number of firewalls available. Presumably you want to use a
linux fw. I prefer OpenBSD but that's just me. Another one I like is
freesco.com. Simple but decent fw that fits on a floppy.
On Monday 22 April 2002 12:00, you wrote:
> I am kinda young in the LINUX world and I have lots of questions to ask.
> So, I thought this was the best place to ask them.
>
> I know that Red Hat comes with a firewall. When you activate it how do you
> know the firewall is blocking all of the ports. For example, if you want
> to block people from ftping to or from your site you tell the firewall to
> block ports 22 and 23 (something like that). I understand that but what I
> don't understand is that there are more ports that are being used by the
> system and the system is waiting for a call by the programs using the
> ports. So, how do you know that ALL the ports are being blocked so that
> ONLY valid usage is being used and no hackers in your system?
>
>
> William
--Steve ________________________________________________________ HTML in e-mail creates out-security, and more spam. By using it you teach others, less knowledgeable, that it's safe to use.
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