hi and welcome to Cyber A doubt I t My name's Anthony and I'm your local subject matter expert here for Network Plus And today we're gonna be talking about how different devices and protocols relate to R. O S I model. So let's take a look at some of the different types of protocols and devices that we may encounter on networks and see if we can identify what
layer of the O. S I model they would fit under.
So first we have Mac addresses. Now Mac stands for media access control addresses, and we've talked about how MAC addresses are unique addresses that are encoded by the manufacturer onto network interface cards. Each of these network interface cards has a globally unique Mac address,
but we typically don't route using Mac addresses. Mac addresses are
used for just our layer to data link layer. We can't route using Mac addresses, but we do point information to specific devices to specific network interface cards. Using their Mac address, our Mac addresses what will consider as our physical address. It is the physical address
of the network interface card on our machine.
Now, in contrast to Mac addresses, we have I p addresses. I P addresses are able to be routed over networks over around the world even,
And our I P addresses are layer three in our network layer. Our network layer in roos I model is often referred to as our I P addressing layer. And as such, our I P addresses fit right in there now R I p addresses are not physical addresses. I p addresses are actually logical addresses
that are mapped to a physical address.
We have a single I P address that's mapped to a physical network interface card. A physical Mac address, excluding I P addresses that are in our broadcast or R I P addresses that are in our multi cast range. But we'll talk about those later in our I p addressing checking our i p addressing section.
But typically speaking, our I P addresses are going to be a logical address
that's mapped to a single physical address on a a network interface card. As such, our I P addresses are going to be layer three.
Next is are you I 64 now, Ari, Life 64 is another name for our i p v six global unit cast now. R I p v six r i p Version six is a much larger set of binary digits that we can use to create i p addresses.
R I p r I p Version six
is a much larger addressing space than our i P version for But we will talk about our i p version six and the differences between our i p version six later. But one of our I p address class is one of our I P six address types Is global unit cast now global. You know, CASS is
undressed that specific
for a single network interface across the world, so we could send information to a global unit cast address and it would be rideable around the world to a specific device. Because of this, because our I p v six global you know, cast is not a logical address map to a fickle physical device.
A global unit cast address is an address that is
specific for a single device. It's considered layer to data link because
we don't have to route or Tran Tran translate that address to a Mac address in order to acquire a data link. Our I p v six global, you know, cast or are you? I 64 would do that for us. It would automatically just globally connect to one specific device.
Next we have frames. Now, frames are our layer to our data link layer, but they're layer to protocol delivery unit. So it's a segment of data with the beginning of an end that we're using on the layer to level. So when we're talking about segments of data and we're referring to them in the layer in terms of our laywer, too,
we're for we're referring to them as frames.
So our frames will want to remember our layer to protocol delivery unit.
our packets. Now, our packets are going to be very similar to our frames, but they're going to be our layer three protocol delivery units. So we're talking about transferring data on a level three level on our networking level,
we're gonna be talking about packets, packets, and again, they're just segments of data with the beginning and an end, and we're sending them across our Layer three network, and as such, we refer to them as packets. Next, we have our switches. Now,
switches are our devices on our network, which allow us to connect multiple devices that are on the same sub net.
So if we have multiple computers with an I P address in the same sub net in a room that we don't have to route data to, will connect them via switch now because we don't have to route that data because we don't necessarily need an I. P address
to communicate with these devices. We do communicate with with an I p address, because that's how our data typically communicates.
But we don't meet an I P address in order to make a connection with that device. We could send out a way we could send out a d a C d h cp Discover message out to our network and that's going to refer back to us, isn't without an i p address, and people can address us and consent
Ah, a message to us specifically without us necessarily needing an I P address. So because of that, our switches are going to be performing at a layer to level at a data link level and they, uh, map to our Mac addresses. Now we do have switches that can
who we are and Matt specific packets directly to us or we make, and we may have switches that's in packets to everybody. And then as it determines, Okay, this Mac addresses on this port. This Mac addresses on this port are this computer. This computer with this Mac address is connected to this port on me.
It begins to make those map ings,
so because of that, we consider that layer to because it's working with those Mac addresses
now. We also have our routers, and routers are sometimes referred to as a layer three switch. Now the sometimes referred to a layer as a layer three switch because they allow us to connect to multiple different networks. They allow us to rout addresses I P addresses and send data across these multiple different networks
because we're working with I P addresses because we're routing data.
Our routers are going to be layer three, so
we need to have sort of an intermediary, and these are multiple layers. Multilayer switches now are multi layer switches. A lowered our devices that can perform on layer to or layer three
their devices that may just perform switching functions, but if necessary, can also be performing routing functions. So these will be considered our layer three switches. Let's finish up with some of the rest of our devices here. Now, we also have a hub now. Ah, Hub is sort of like a dumb switch.
Ah, Hub Hub just takes in all of the incoming
data that is receiving and then just sends it out to everybody that's connected to it. So it allows us to pass data onto multiple computers in the network, but it isn't going to be smart. It isn't going to do any mapping of any Mac addresses, and it's not gonna do any mapping of any I p addresses. So it's just gonna take in that data and just send it to everyone. So it
doing anything as faras routing. It isn't doing anything with I P addresses. It's just letting us connect from one point to another. So because of that, our hubs are going to be layer to data link, and it passes the information to everyone that's connected to it. It just takes it and it passes it, and it allows us to make a data connection.
We're also gonna have encryption devices. Now it's encryption devices may be physical devices on our network that perform encryptions at one point and then decryption at another point.
Now these encryption devices are going to be layer six devices layer six being our presentation layer layer six formats. Our data does encryption and decryption as among other mother other forms of data form formats. But because encryption is a type of beta format,
it is a way that we're modifying our data so that it can be viewed.
Or it could be encrypted and then transferred over the network. Our encryption devices are gonna fall under that layer. Six. Our presentation because it's formatting our data.
Then we have a cable, and our cable is a very easy to tell. Is a layer one. It's a physical device,
something we can hold it, something we can plug in and connect. It's gonna be a layer one physical device. A network interface card is also a layer one physical device.
A bridge is going to be a layer to data link device. Now, bridge is considered a layer to device because a bridge provides point to point connective ity. Aah! Bridge is going to allow us to connect or whether it's through a wireless bridge that we set up from one point to another or an Ethernet bridge that we set up.
A bridge is just going to provide one point to another point, much like a bridge connective ity. So we're gonna have a bridge as our as a layer to device.