Hello and welcome back to I C ndy one interconnecting Cisco Networking devices. Part one
this is Episode 123 Datalink Protocols.
I am threatened. Daryl and I will be your struck for this course.
And the last video went off over small office, home, office and enterprise lands along with some Ethernet cable standards and pinots.
In this episode, we'll be covering what is the data link protocols and how they were used.
So it's a quick learning objectives here. We're gonna learn about the data link protocols, which is the thing that protocol on the Mac address
never look a little bit into how it works in with error detection.
So quick, pre assessment Here.
What components? What two components make up a Mac address. And again, I'll give you a few seconds to go ahead and positive video.
Okay, Hopefully you got it by now, and hopefully you got these answers as well. The organizationally unique identify R o U I and then the vendor assigned
So quick breakdown of an eastern at frame. Remember, that is the data unit for later too.
So we're gonna have our in the header. We're gonna have a preamble,
for synchronization. S F d, which is the start? Framed a limiter, which will signify that the next bite is the Destination Mac address,
which now we have a six bite destination Mac address.
Oh, by a six bite source. Mac interests, which would be you as the sender
and then a to bite for type, which will determine
what type of frame it is when its I. P v four i p. V six. There's a few others. If you actually look up
the IEEE ether type, they have a whole
Ah, it's a very large page of all the different either types,
and then we get into the actual data and had This is the I P V for packet. Usually it's a layer three packet. It's a minimum of 46 bites to him back some of 1500 bites, so it's under 46 bites. What it does is that's where pads it to make it to a minimum 46 bites.
Finally, we get to the
Datalink trailer, which is the F. C s of frame check sequence.
It's kind of almost like Think of it as a hashing algorithm so each side does a hash of the frame,
and it checks to see if that matches what the frame check sequences.
And if it doesn't match, it just kind of throws the packet out. It doesn't do any actual a recovery like in the transport layer,
so Mac address stands for media Access control. It is 48 bits long or six bites or 12 hex long,
so it's a quick math. One bite equals eight bits, and one hex character is four bits again. L u I stands for organizationally unique identifier, which is the 1st 3 bites of the Mac address.
And then the vendor is signed for the network interface card. It's all three bites, so if you look in the picture in the bottom right, you can see the first half is the organizational unique. Identify yourself. Let's see if you have an intel. Carter. You have a real tech card.
All of them have their own specific
three bites portion there.
This is sometimes referred, or the entire Mac address is sometimes referred to is a burned in a dress.
Or it could also be called land address, Ethernet address, hardware address. A lot of times physical address.
So if you wanna look up your Mac address if you're on Windows, the easiest way to do it here is to just bring up command, prompt
and then run. I peek and fig slash all
go ahead and ran it off. So the right here. So if you look at my VM were Box
Veum Where Internet and after for Veum Net eight. You'll see right our needs that the physical address
should start 005056 See zeroes. There's our eighth.
You'll see that is a physical address for that adapter.
And if you're on Lennox or Macintosh, what you're gonna want to see is an if config dash a
so I got to bring that up.
So here you can see the V box
adapters here. So we're looking for Is this portion here? The hardware address.
It's on the next slide here. We're gonna look at the group addresses in the tight field,
so I Tripoli will define two different group addresses, which is the broadcasting dress being all EFS,
meaning it. It's gonna be to be sent to everyone on that
on that broadcast domain everyone's gonna receive that frame
and then you have a multi cast address that actually starts with 01005 e
knows we do use for specifically everything's
so some comments, field types and that he saw in the frame header. There
is 080 zero's I p four frame or 86 Delta Delta is an I P v 61 And again, if you look up Tripoli ether type, you can look at all the different frame types.
All right, so quick, Post assessment here to end up our
What is the f. C s trailer? D'oh! And again, it will be a few seconds to go in positive video.
All right, Hopefully you got the right answer. It is air checking.
Remember, the transport layer does the air recovery,
and the other one is package carriers. So the next episode will be looking at how switches and hubs work with frames.
So if you want to stick around for that
and of course, if you guys have any questions or if you need some help,
go ahead. Feel free to send me a connection.
Otherwise, thank you for washing this course, and I look forward to seeing you in the next lesson.