Hey, everybody and welcome to the next video.

So in this video, we're gonna be going over Networking.

This is going to be a high level overview of what networking is in a nutshell.

And then we're going to dive a little deeper in different parts.

Now, what is networking?

Networking is the connection of computers to share some sort of resource.

Now, whether that's a website, file sharing, just transferring data, whatever the case might be, it's to share resources.

Now, the Internet is based and powered by networks.

So just the Internet is just a compilation of networks from different spots in the world that are all sharing resources.

Commonly you'll hear networking people refer to it as an endpoint or a node.

It entirely depends on who you're talking to.

But in general cases, we're going to refer to it as a node.

Now, what travels over a network is a packet.

Now a packet is a set size, most of the time, depending on the protocol used, is a set size of data that is transferred over a physical medium, which is the wire, the physical wire that runs from the computer or the wifi or whatever the case might be.

It's some sort of medium, to another note on the network.

Now, commonly TCP, IP and UDP use this type of structure, the packet.

But most other protocols that you're going to use inside of TCP or I'm sorry, on top of TCP or and on top of UDP are going to use a packet as well.

This is a basic understanding what a packet is, we will dive a little bit more into that in future videos.

Now, the networking medium.

Here are just a few common.

We have UTP or unshielded twisted pair and then we have STP for shielded twisted pair.

Now, what you're commonly going to be running into, at least from a home network standpoint, or maybe in a networking closet you're going to see unshielded twisted pair.

Now, what happens between shielded and unshielded is the wrapping around the wires itself to help avoid any disturbance in the wire itself.

Now, I'm not going to go too much in detail of how twisted pair looks like.

There's a lot of tutorials out there to show you how to make your own twisted pair, the shielded parts are a little bit different because you have to have that ring around it.

However, I'll leave that to you guys to look up a little bit more detail.

Now, the coaxial cable is probably what you're going to be most familiar with as far as what you see on a daily basis.

You're going to see when your modem is connected to the wall, a big cable with a giant spike through the middle that goes into a wall that you have to turn for 20 years, that's a coaxial cable.

Now, again, I'll leave that specific types of cable and what they do for you guys for homework.

And then at an enterprise level, you're going to be dealing with fiber, which is made of light.

So, again, look at that, look that up.

There is multiple different types of connectors for fiber cables, there's different types of fiber cables.

But just understand that it's commonly used as a backbone or the base line of the network is normally a fibre connection because it can go much longer distances.

What I also want you to understand is for each cable, the different types of cable have different lengths.

So you can only go so far on a shielded and unshielded twisted pair cable before the data needs some sort of repeater in the middle to boost the power again and have it send a full signal fiber on the on the station, go much farther than any of the other three.

So it's important to understand that from a networking perspective, as far as a red teamer is concerned, you won't need to deal with this too much unless you start getting into fibre taps or any type of wire tap which you might do.

So just keep that in mind, ahead of time.

Now, RFCs.

Now, an RFC is a request for comment.

This is some sort of publication.

Normally this is about a protocol or an algorithm or any type of document that needs to be standardised.

Now, this fully defines the type of technology and what it does.

So if you want to look up, if you want to Google HTTP 1.1 RFC, you're going to find a gigantic document of exactly how HTTP works and what how it's structured and how everything.

TCP has the same thing, IP has the same thing.

So you can go and look up in RFC.

I want you to understand what RFCs are.

Now, you're two very well find yourself going through and reading the whole thing.

You might be looking for a specific thing like you don't know how to interface with a particular protocol.

So maybe you need to look at the RFC to identify that.

Just keep that in mind what an RFC is, because you'll see that that term thrown around a lot.

Is there an RFC for it?

Is there not?

So it's a good place to look up information when you want to get really low detail on exactly how everything works.

Now, as far as networks go, there are a few network topologies.

Now, topology is a structure of the network.

So what it how it functions as a whole and how it how it looks like.

So there's a few of those bus, ring, star, mesh and hybrid.

Now we're going to go over each one of these in a second.

Now on a Bus Topology, you can see we have the one line going to the middle.

Now, that one line going through the middle you could think of that is your backbone or your fiber.

And then everybody else connects into that wire.

And the nodes in this case are whether it's a server or a workstation, it doesn't matter.

But I want to understand that a bus looks similar like a bus to straight line and it's got nodes on each side, not it's commonly used on the back end.

And each one of those nodes would normally be like a router or a networking closet or some sort of things like that.

Now, a ring also known as the token ring, and it looks like we got a straight line over here.

So a token ring is when everything connects to the next one in the line and eventually makes it circle.

The problem with this is if one drops the node before, it can't reach to the other side.

So there's limitations on each type of topology, which is why we'll go over some of the other more used ones, but understand what with the ring topology it looks like.

Now stars, pretty similar.

They all connect into one sort of networking device.

However, if that network device fails, all of them are offline.

They can't talk to each other.

So that's why it's looking like a star.

Now, a mesh is getting into more of what we're used to on a regular network.

Now, keep in mind of mesh.

Mesh is one of those things that we're it's it is a combination of a few different ones.

So you can have a backbone as well.

But you also see a star topology in here as well or things connected to a networking device.

But you also see nodes that connect to other networking devices, which is not common in a start up typology.

So it's kind of meshing some of them together.

And it's good to understand that mesh is more of what we commonly use.

But hybrid is, again, what we normally use on a day to day basis.

Now, I know the document here looks a little weird, but bear with me here.

In this case, everything connects to each other, so there's always a path to it.

Now, between mesh and hybrid is what our networks are commonly done today in the backbone of the network, going from like, for example, site to site or for example, down the street for the Comcast fiber line or Google Fiber.

They have the main line that goes down the street and then connects off to think of these nodes as houses.

So hybrid and mesh kind of you combine those two together and you have a structure of what our network sort of look like now.

Now you can design the network however you want.

But in most cases you're going to see a mesh of switches that handle a certain amount of hosts and those switches are attached to a cabinet which is on a backbone.