Welcome to Cyber is Video Siris on the Comedy of Security plus 5 +01 Certification and Exam.
I'm your Instructor, Rahm Warner.
Please visit cyber harry dot i t. For more information about this certification and many others.
Before we dive into all the different technologies and tools associated with cyber security, you need to understand the basics of networking.
For the next few minutes, I'll be going through networking all the different layers associated with it and how it works to communicate across the Internet.
We need to start by defining what a network is.
A network is basically a way to get things between two end points.
Our goal is the basic understanding of common modern networking technology and terminology. So in this quick video, I'll explain the analog digital and applications you'll see with networking
protocols air used with networking to help move the information from one end point to the other. It's basically just the set of rules, it explains. What do you want to do? So it's an application.
Where is it going? Add dressings. A. The I P address.
How are you going to get there? The types of media so like this is an MP four video.
And did you get there? The acknowledgements An error checking that happens within networking
throughout domain to We'll talk about the different layers within the OS IE seven layer model. So I am for you to be very familiar with the OS I model. You see it on your screen, also known as protocol stacks. The represented in layers To help understand
how things traverse a network
you need to memorize either from the top down or bottom up.
The bottom is the physical layer than data link, network transport session, presentation and application.
You see other representations that are based on the OS I model.
Let me explain each layer
layer. One is that physical layer could be cat five. CAF, Ivy Cat six, which is twisted pair copper, wire fiber, cable modems or even WiFi
after the physical layer is the data link layer, also known as layer to.
This is where you'll find Mac addresses the Media Access Control address for that specific device.
Each network interface card or nick
has an associate ID Mac address. You see an example on your screen. This is unique to the device, and the vendor
Let's practice looking for our Mac address on some common operating systems in the windows. Open a command prompt or terminal within one X or OSX
and Windows type. If config slash all
or Lennox, its I P can fake,
you could also practice on that
personal computer in your pocket known as a smartphone
on your screen. You see an example of me doing this on a laptop by one's own.
Highlighted in yellow is my Mac address.
You should try this on your own devices. Make sure you fully understand Mac Address ing
after layer two courses. Layer three network layer. This is where network packets are routed. Uses what's known as encapsulation between each of the layers
at the network layer. You'll find I P addresses, also known as the Internet Protocol addresses Network Layer also has address resolution protocol Are two types of protocols
to resolve Mac addresses with I P addresses.
If you refer back to the if configure example, I showed you can see my local I P address again on any device you have practiced. Looking at both the Mac address and the I P Address
I p. Address ing for version four has four octet. It's Can you see the example on your screen? Each octet consists of numbers between zero and 2 55
or 00 and FF and hacks.
It works sort of like a phone system with area codes to the left and the prefects.
I P Version six uses 128 bit addresses. So theoretically, there's two to the 128th power number of I P addresses for I P v six yen. If you type if config and windows or i p config in Lenox, you'll be able to see whether you're using I p v four
I p v six
or both. Also at this layer is I p domain name resolution or D N s. It's like looking up names within the old fashioned phone book equating your girls with the associate ID I p address uses Ah, hierarchical system for resolving names.
You can use wire shark to see how d and s resolution works. There's also the NS Look up command within windows to be able to look up an I P address
on your screen. You see the resolution between Google and its I P address
transport layer is at layer four.
Protocols of this layer provide host a host communication service is for applications uses incoming and outgoing ports to and from the server.
Common examples are http over Port 80 and https over Port 443
There are two major types of transport layer protocols.
TCP transmission control Protocol is connection oriented and provides error Checking
UDP user data. Graham Protocol is connection lis and used for streaming like this video.
So right now I'm talking to you over UDP.
If I were to confirm all of our communications, then it would be T. C P.
To make a TCP connection uses what's known as a three way handshake.
It starts out by saying sin to synchronize
the client, then response back with a sin AC. Also synchronizing but acknowledging it, the source replies with acknowledgement and conversation begins.
It ends with a thin packet saying, Feeny, we're done for final
using wire shark, you can see the TCP three way handshake. An example is on your screen.
I'm gonna jump up toe application layer layer seven.
This is where the applications talk to each other.
For example, email over simple Mel Transport Protocol Web http File Transfers, Transfers FTP and time Network Trot Time protocol NTP
you see the different layers of the O s. I model
Refer to this quick summary as you're reviewing this to make sure you understand all the layers as we work through Domaine two of the security plus exam.