Welcome to Section two in this section, we're going to go over the basics of networking, we're going
to really get you a foundational understanding of what exactly is a network, how the network works,
as far as how a network communicates, how they communicate with different types of information and
everything that you need to know about how a network works.
Right.
So let's go right ahead and jump into the network basics section two.
So just like I mentioned in this section, we're going to go over some of the networking basics so that
you can get a basic understanding, right.
Foundational understanding of how a network works.
So what we're going to be going over in this section is what exactly networks are, how they function,
what are the different components, the aspects of a network, and then how data travels across the
Internet.
It's important for you to know how data travels and what type of forms, what type of form factors so
that you'll be able to capture that information as a hacker.
Right.
As an ethical hacker and be able to put your mind into the mind of a criminal right into a black hat
mind so that you can be an effective cybersecurity ethical hacker professional.
And then you're also going to learn some important ports and protocols, the differences between a public
and a private IP address and really what an IP address is as well.
And what exactly are subnets and then a practical example of a typical home network.
So let's go right ahead and jump in here into what exactly are networks.
So a network occurs when two or more computers are linked together and can share resources with each
other.
And so on a network, your computer can technically talk to all the other computers on a network.
Right.
And so if they're all connected, then they can communicate back and forth and get access to each other
to different types of information.
And so the good example of a network is the Internet, right?
The Internet is the largest network in the world, and it consists of billions and billions of devices
that communicate with each other due to their connection through the Internet.
So let's go over some of the different types of networks.
So we have a personal area network, a pan.
This is essentially a convenient one person network.
This is typically going to be through some sort of device such as a headset, wireless keyboard, wireless
mice, printers.
Right.
Barcode scanners, gaming consoles.
This is where you're going to have a simple, small, very short personal area network.
Then we have a local area network, a LAN.
If you work in some sort of office setting, then you most likely have been exposed to are aware of
a local area network.
This is the most common for a lot of local businesses.
And with this there's typically a few different computers that are linked to one or two printers.
Also a scanner, maybe a single shared connection to the Internet.
I remember years back when I had my office job, I remember the company had four to five different printers
in the actual office.
And depending where you were working, you had access to a certain printer.
So if you were like, let's say, in the north side of the building or the office, then you would have
access to one type of printer and scanner.
And then if you were like on the west side or on the south side of the office building, then you would
have access to a different printer.
So that's how you can think of a local area network.
And then we have a metropolitan area network.
And this is essentially where it covers an entire town or city.
And then we have a wide area network A when this covers typically a geographical area, you can think
of the Internet as a wind that covers the entire world.
And then the biggest differences between the Internet and many other Panj lands and wins, it is open
to the public.
Right.
Anybody with an Internet connection can actually log on and look at specific websites.
Right.
That are hosted on the Internet.
So one of the things that you need to keep in mind here in differentiating the different networks is
whether or not they're open to the public.
Right.
So you want to think about are they public or are they private?
And one of the other types of networks that you may or may not be familiar with is an Internet.
Now, when I was working in an office setting, we had a online database, which was an Internet for
the company itself, 500 employees in the company when I was working that zones.
And what we had is a database essentially where we only could get access from within the company or
if we had access to the company network.
Right.
And so nobody else outside of the company or anybody else outside of the the actual company had access
to the actual network or the Internet because it was only for employees.
And so that's a private internal Web platform.
That holds information data, right, for the actual company, and that can also be susceptible to attacks
and where, you know, hackers are trying to gather that information because it's private to that company
and then we have a virtual private network.
This essentially allows you to change your, quote unquote, identity online where you can have a different
IP address, different location, so that you can securely look at a get access to a network, a private
one or a public one without leaving any tracks or any traces of who's actually behind the computer.
And so now let's go over the permissions and network security.
So here's the thing.
When it comes to machines being on a network, right, they're all connected.
However, just because they're all connected, it doesn't automatically mean that each machine, each
device is going to have access to the other one.
And so the only way that you're going to be able to get access to the other information on the other
computer or device is if it's given access.
Right.
If you're given access to that information.
Just think about on the Internet, you can gain access to billions and billions of Web pages.
However, you can get access to every single file.
Right, every single page on every single computer that's hooked up to the Internet because some pages
are private, some pages are going to be only for internal use.
And so just because a device is connected to an actual network, yes, they're all essentially connected.
But that doesn't mean they're all going to be able to have access to each other's information.
Permissions and security are central to the idea of networking.
You can only access information, like I mentioned, to information and resources only if that individual
gives you permission to do so.
Right.
And so with hacking, which you're essentially doing, is you're gaining unauthorized access to a computer
network by cracking passwords, defeating any type of security checks, bypassing antivirus, whatever
the attack may be.
Right.
You are hacking because you're getting unauthorized access.
Right.
And to make a network more secure.
Oftentimes, companies, organizations.
Right.
They will install firewalls.
And this can either be like a physical device or a piece of software that's running on your machine,
or it can be both.
I remember when I worked for Zones a while back, we used to sell different type of physical devices
that acted as firewalls that secured networks.
And a lot of times these helped with incoming spam from email incoming attacks.
And so if you look at the image on the right, these are essentially walls that are put up where individual
hackers, let's say, you know, being able to bypass one stage, maybe they get, you know, some sort
of access to information of some sort.
They are essentially reaching the actual end of their destination.
However, they are getting blocked because there's a firewall right before they have the information
that they're looking for.
So firewalls are extremely powerful for being able to block any type of attacks, you know, that are
looking to gather information, steal data, whatever that may be.
As far as having your antivirus there initially or having any other protection, they're having a firewall
adds that extra layer of protection as well.
OK, so we talked about the different types of networks.
We talked about the actual network security, the different things that are involved with the permissions,
you know, firewalls.
And so now we want to go into a little bit more depth as to what exactly is a network consisted of.
And so, as you can see on the right hand side there, that's a visual representation of a network.
So essentially here to make a network, you need nodes and connections.
And these are essentially the links between then and now.
In most office settings, you're going to have wired connections because these are typically going to
be the most strongest as far as connection speed, and they're oftentimes more secure as well.
And so each node on a network needs a special circuit known as a network card.
Now, a node is really just a device, right?
A network card here is a network interface card that is essentially there to get the actual connection
established.
And this is a lot of times through either wireless or wired, it can be both.
And so each network card has its own separate numeric identifier.
And this is known as a media access control or a land Mac address.
And so in that code is a bit like a phone number.
So any machine on the Internet can communicate with another one by sending a message quoting its Mac
code.
So this is how these actual network interface cards look like.
You can see on the left hand side, there's one for a wired connection.
And then on the right hand side, that's for a wireless connection, and especially now there is cards
that have both capabilities for wired and wireless as well.
And so let's look at the Internet as a network.
And so just like highways or railroad lines that connect towns and cities, you know, country, states,
whatever that may be.
Right.
Computer networks are often very much so elaborate and computer networks are very much so the same.
They're all connecting networks all around the world.
And so the Internet, for example, is based on a set of well defined connections called the Internet
backbone, and it includes a vast set of submarine cables under the oceans.
And so if you look at the right hand side, the image there at the top, you'll see all of the connections,
the cables that are connecting the entire world.
Right, so that everybody in the world can gain access to the Internet.
Now, as you can also see, there are some areas that don't have as many cables and connections which,
you know, lack, you know, some Internet or some sort of Internet connection.
Right.
And so when we look at these cables here, it's very interesting to look at that they are just three
inches thick and have a total capacity of between 40 gigabits per second and 10 terabytes per second
and latencies that are close to the speed of light in just a few milliseconds in duration.
So you can see these are very powerful cables here.
If you ever thought about how everybody in the world is connected through the Internet, how can everybody,
you know, just get online and be able to look at some of these Web sites across the world or get on
a Skype call with somebody across the world, is because of these cable connections that are essentially
allowing us to all be connected.
And so that's going to be here for Section two, overview of the Networking Overview Network and BASIX.
And we'll see you on the next one.