The firewalls that we use today on our computers
and in our networks are what we call stateful firewalls.
That's because the firewall remembers
the state of the traffic that's going through it.
Here's an example.
I have a client computer on the left side with a firewall.
This might be us at home behind our home firewall.
The internet is on the outside.
And out on the internet there might be a web server
that we would like to communicate to.
And of course, the bad guys are also on the internet as well.
With a stateful firewall when we send traffic to a web server,
the firewall sees that traffic and remembers
that we sent that information to the web server.
And it is expecting a response back from the web server.
And when that web server responds back,
the firewall will remember the state
of that particular session and allow that traffic
to come through back to our client computer.
Windows includes its own software-based firewall
called Windows Firewall.
We can use this if we don't happen
to be on a network that already has another firewall
or we might use it in conjunction
with an existing physical firewall that's on our network.
You can access Windows Firewall from the Control Panel
under Windows Firewall.
There's also a setting in Windows Firewall
for advanced security.
You click the Advanced Settings, and you'll
be able to access some of the more advanced features.
And in this video, we'll look at both the basic features
of Windows Firewall and then we'll also
get into more of the advanced features as well.
Windows Firewall includes a list of fundamental firewall rules
that are already configured inside of the firewall.
These are based on applications.
There's not a lot of detail in controlling
what is going where.
We're only allowing or disallowing
certain applications to work on our system.
You also can't define any specific IP address ranges.
There is no scope associated with this
so all devices can communicate in and out using
this particular application.
There's also no connection security rules either.
We can't set up specific detailed information
about these.
If we wanted more control over these,
we would need to use more of the advanced features
of the Windows Firewall.
On my Windows Firewall, I have three different windows
network configurations.
One when I'm connected to my Windows domain, which
I'm not currently.
One on my private network, and then
on my guest or public network.
And I've currently configured this system
to act as if it's on a public network.
For each of these network settings,
we can see more information about how
it's configured by clicking on Allow an App or Feature
through the Windows Firewall.
And then we can see all of the different applications that
are currently configured and we can
see how they are set for the domain configuration,
the private configuration, and the public configuration
of networks on my computer.
If we wanted to allow another application,
we can click Allow Another App and we
can specify an application.
But as you can see, there are not
a lot of options other than allowing or disallowing
what's going through our firewall
based on a specific application.
To have complete control of the Windows Firewall
you need to use the Windows Firewall
with Advanced Security.
This allows you to set inbound rules of traffic that
is inbound to your computer, outbound rules on what's
allowed to go out.
You have connection security rules.
We'll look at those as well.
And you can set very granular control.
You can set what application, what port,
any predefined services, or customize
any range of different items between all of those.
When you're setting up custom configurations,
you can also specify things like the program, the protocol port
number, the scope, the action, and the profile
that you're going to use.
To use the advanced features, we would
select in the left-hand menu Advanced Settings and that's
going to launch a new window that
shows Windows Firewall with Advanced Security.
This shows your breakdown of the profiles.
And you can see on the left-hand side
we have inbound rules, outbound rules, connection security
rules, and monitoring.
If I choose inbound rules, you can
see there are a large number of predefined inbound rules
in our Windows Firewall.
And if we click on any of these, lets
choose Skype as an inbound option,
you can see the different options
for the Skype application.
This one is allowed for this connection.
The different programs and services associated with it,
any remote computers so we can set
some detailed scope for this particular application.
The specify protocols and port numbers that might be in use.
And there are other options as well to really refine
exactly what traffic is allowed inbound
and what traffic is allowed outbound from our computer.