-: Back in Network+, you learned all about firewalls
and we talked about them from a network perspective
where they were dedicated pieces of hardware
that sat at the edge of your network
and controlled what went in and what went out.
Well, here in Security+, we're going to
talk about personal firewalls.
These are software-based applications
that protect just a single computer or server
from unwanted Internet traffic.
Now, these are also referred to as host-based firewalls.
These firewalls work by applying a set of rules
and policies against traffic that's attempting
to come into or go out of our protected computer.
For example, if there's a computer that's a web server,
then it should be accepting incoming traffic
on port 80 and port 443. But if it's a desktop computer,
there's likely no need for these ports to be left open.
Instead, the firewall should reject any inbound
attempts to access these ports.
Because we're talking about software based firewalls,
we also have to consider what operating systems
are being used, whether it's Windows, Mac OSX, or Linux.
With Windows, we have the Windows firewall.
With OSX, with have PF and IPFW firewalls.
And with we Linux, we have iptables.
First, let's discuss Windows.
In every version of Windows, there's its own
software-based firewall already built in and available.
There's usually two types included.
One is a basic version that's found
within your control panel, and then
there's a more advanced version called the Windows firewall
with advanced security.
This advanced firewall can be accessed by typing
wf.msc at the command prompt.
The basic firewall is useful for most home users,
while the more advanced version is well-suited
for businesses and systems where more in-depth
configurations of your inbound and
outbound traffic is required.
Next, we have Apple's operating system, the OSX,
which has a built-in software firewall for Mac users.
A basic version of the firewall is accessed
through the system preference panel
under the security and privacy panel.
In addition to the graphic user interface-based firewall,
there's also a command line version.
This version is called PF for packet filter.
It's available in OSX 10.10 and higher operating systems.
Packet filter is the name because it's essentially
what a firewall is designed to do.
It filters packets.
In older versions of OSX, there was a
different command line firewall used
called IPFW, which stood for Internet protocol firewall,
but that program was replaced by PF
for most modern versions of the OSX operating system.
Both PF and IPFW are also used in
the FreeBSD operating system,
which is what OSX is actually based on.
Just like Windows and OSX, Linux has
its own built-in firewall too.
In Linux systems, this program is called iptables
and can be configured from the command line
using different accept and reject rules
based upon the type of network traffic
that's expected and the port being utilized
for that communication.
Besides these built-in firewalls for
each of these operating systems,
many anti-malware suites also have their own
software firewalls included too.
For example, if you're using Windows,
you may have a firewall from Symantec, Mcafee,
or Zonealarm.
Software firewalls, like all software,
does need to be updated though.
All software is vulnerable to attack,
and therefore, you need to ensure
your host-based firewalls are regularly
updated with service packs and software updates
to ensure that they remain safe and secure.
Some users don't like using host-based firewalls though
because they do end up using some of
your computer's processing power.
This has to happen so that it can check
all of that network traffic
against each of the rules and policies
that it's been assigned.
Because of this, some organizations,
instead, like to rely on dedicated hardware
and network-based firewalls as their
first line of defense.
In fact, most small office and home office
wireless access points and routers
have a built-in hardware firewall
that can provide protection across the entire network
instead of just relying on each
individual computer's software-based firewall.
That being said, it's still better to run
both a personal software-based firewall
and a network-based firewall to provide you
two layers of protection and help establish
a more fortified defense in depth security strategy.