- Let's talk about the difference
between public IP addresses and private IP addresses.
Up until now, we've been talking private IP addresses.
And an example I've been using a lot is 192.168.1.1.
This is a private IP address.
It means it's supposed to be used internally
within your local area network.
It also means that it does not face the internet directly.
That's why it's called private.
Public addresses, however,
they do face the internet directly.
An example would be 65.43.18.1.
And this IP address is known as internet facing
or public facing.
And that means that anybody around the world
can see that IP address.
Anybody around the world will not be able to see this
because it's behind usually a firewall
and behind some type of network address translation device.
When it comes to public addresses
you have to be very careful with security.
You wanna secure any servers that are on public addresses
to a certain extent.
You're gonna wanna leave them open somewhat
so that people can gain access to services,
and everything else you're gonna want to firewall
and close down that server, make sure it's secure.
And we're gonna show examples of public IP addresses,
private IP addresses in Windows now, or just in a second.
What I want to show real quick though
are the private IP ranges that you should know.
Besides 192.168, there's also the 10 network.
And the 10 network could be anything.
It could be 10.254.254.0.
It could be anything after it,
but it's gonna be something on 10.
And then the other one,
which I had mentioned before is 172.16.x.x.
That's gonna be the network number.
Also 172.17 all the way through to 172.31.
Those are the main private IP numbers
that you're gonna need to know.
We're gonna go over those again
when we look on the computer.
So let's get into Windows now and show some examples
of public and private IP addresses.
Okay, so we talked about in theory
public IP addresses versus private IP addresses
and the differences between those.
Now let's show it a little bit in the command line.
First of all, let's show a private IP address.
If we do a simple ipconfig,
we'll see once again our ethernet adapter
and the address 10.254.254.204.
That address is a private address.
Anything on the 10 network is gonna be private.
That's internal.
And the only computers
that are gonna be able to connect to this are local systems,
systems on the local area network.
But you don't have to worry
about computers on the internet connecting to you.
If you want to have a system that anyone can connect to
then you want to have some type of server on the internet
and then you would want a public IP address.
So let's give an example of that now.
I'm gonna connect to the example.com domain
with the ping command,
which will then show its public IP address.
So we'll do a ping and example.com
and you can see the replies come up now.
I'm pinging this from my computer,
but example.com is in a completely different area
on the internet.
And you can see the address here, 93.184.216.34.
93 is a public IP address.
Anything that starts with the class A 93 network
is gonna be public.
So you got a little example there with example.com
of a public address.
Remember, the public addresses are used by servers
or any computers that need to be internet facing
so that anyone around the world can connect to it.
But the private address is something that you use usually
for all your local computers, all your clients on your LAN.
And an example of that
is our laptop that we have right here
that's using the IPv4 address 10.254.254.204.
So know your differences between private and public
and take a look on your own system now
and take a look at your own address
and maybe try pinging some websites and domains out there
to see their public addresses.
And that wraps it up for this sub lesson.