- [Instructor] Host firewalls are stand-alone firewalls
that only protect a single host.
Firewalls can be categorized
according to the scope of what they protect.
The remaining two types of firewalls.
The first type is host firewalls,
and the other type is network firewalls.
Our focus in this lesson is host firewalls, for now.
Host files monitor activities occurring
on network interfaces on a single host.
They make decisions on whether to accept or reject packets
for a single host.
Major operating systems
come with their own built-in host firewalls.
Let's first take a look at one provided by Windows.
In this case, we'll look at the Windows 10 host firewall.
To get to the Windows 10 host firewall, choose settings.
Click on network and internet.
And then you can see Windows Firewall here.
Click on Windows Firewall, and here it is.
The default configuration of a Windows Firewall
is to drop all the incoming or ingress packets
to accept all the outgoing or egress packets.
And then, packet forwarding is disabled.
To turn Windows Firewall on or off,
you can choose a network, like this.
And use the switch here.
If you want to introduce a new Windows host firewall rule,
click on, allow an app through firewall.
To add a new rule, click on, change settings.
And then, allow another app.
Next, choose the app you want, let's go back.
If you'd like to make some changes in the advanced settings,
click on, advanced settings.
Choose yes.
Now, you have much more flexibility.
On Linux, the built-in firewall module
is called Net Filter.
Let's check out my Ubuntu host.
The default firewall on Ubuntu is Ubuntu Firewall or UFW.
to start the firewall type, sudo ufw enable.
Press enter.
You may need to type the root password
that is given to the administrator password in Windows.
I'm signed on as route,
which is why I don't have to type mine.
If you want to open a new port,
type, sudo ufw allow, and then the port number.
Let's say that the port number is two, two, two, two.
Press enter.
To delete the rule you just added,
type, sudo ufw delete allow two, two, two, two.
Press enter.
Now, you know how to manage your Windows
and Linux host firewalls.
And it's time for you to try this newly obtained knowledge
on your own computer.