Hi, Daddy.
This might have that here again.
In the last lecture I have said that the multicast used the class D for the destination.
Alright, so now we have to go more into details about that to see what direction are being used and
why this right is being used.
And also we have to see about the Mac address, which is the layer two.
So we know that every time any machine will want to send any traffic, so it should have the Mac and
the IP of the destination and the microphone and the IP offer itself.
So we are going to see what Mac addresses we use on the multicast and we are also going to see about
the layer three, which is the IP address.
So let's go directly to the explanation.
So I already have said I wanna reserve the class D for multicast.
Ioana is the organization responsible for all IP addresses in the world, so they have Class A, class
B, class C, class D, and also they have Class E, which is for best interest.
So they have reserved the Class D to be used for the multicast.
You cannot use Class D for the normal unicast or broadcast the traffic that we do.
So it's only for multicast.
Now, there is a difference between the multicast and unicast is that unicast IP addresses represent
a single network device.
So once you put, for example, on your computer, an IP of one or two was accepted, for example,
0.1 then that means that this is a representing a single machine that is a unique custom IP address.
Why multicast represent a group of network devices or receiver.
As I have already said to you that once you want to make multicast, you will send it to a group of
devices that want to receive this streaming video.
All right.
Now let's check the third point.
The range of the IP others is reserved for format cuts as from 2 to 4 000 until 239.255.255.25.
So this is the range that is being reserved for multicast.
Of course, we will see in a moment that not all of this is being used for multicast because there are
some of the that, say sub branches inside this range are being reserved for some other network protocol,
but they are multicast.
So we'll speak about that in a moment.
Now, if someone want to say why it is from 2 to 4 zero zero 0 to 3 9.255.255.255 is because of multicast.
The first four bits of the first octet there are 1110.
So once that are 1110 and one, you play with the other bits which are for the other octet that it will
see that it will start from 2 to 4 zero zero after 239.255.255.255.
Now there are some ranges, as I have said, that the reserves such as the rest of 224.00 0 to 2 to
4.0.0.255.
And this reg is being reserved by Ana.
They use this range for the network protocols.
So that means what you never have to use any of your multicast group from this range from 2 to 4 zero
zero after 2 to 4 00.255.
Don't use this range at all because it's not going to work because those reg are being used for some
network protocols.
For example, if we look, that is the list that I have showed you.
If you know about OSPF, you know that they are hello packets.
They work on 2 to 4 .0.0.5.
So it is for the hello packet.
Did this for the the R and B, they are on OSPF for example.
That is for the version to update.
It is for HRP thereafter updates.
So you can see that all this reg is being used for some network protocol.
So again, do not use ever the rush from 2 to 4 .0.0 until 2 to 4 .0.0.255.
Why do you want to create your multicast group now?
In addition to that there multicast right there is another range that also advised to not use it, which
is 2 to 4 .0.120 24 because this also is being used for some applications.
Now the difference between this one and the one that we have seen them for, the network protocols that
in case you use from the range of the network protocols, which is the first one we see that one that
did not come from network one here.
If you use this, Reg, it's still work, but it will add up having for you some conflict because look,
some of the applications they use from there, they are using from this financial entity that is 2 to
4 011, for example, something like an SS 224016.
So you can see that there are some application being used from this up from this range of IP.
So that means bottom line, do not.
Use when you want to do multicast.
Any of those two ranges 224000 slash 90 4224010 24.
All right, so just put this in your mind.
Now, the last thing that I want to say about the IP address is that as we have a unique public and
private IP address, also we have the same on a multicast.
So iyana the average of the subnet 239.0.0.0/8 to be used for multicast inside our network.
That means what that everything which is 2392020202392552552245.
Is safe to use in our network for multicast.
And you will see when we do the lot, I'm going to use a multicast group from this reg starting from
those three nine or something.
That's something that's something that's not a problem.
So as I review, remember, do not ever use the 224000, the 224010.
And the multicast when you're using the multicast group because those are reserved by IANA, some for
the network protocols and some for applications.
Also, we have shared that the range of the multicast stuff from 2 to 4 000 after 239.255.25.255, which
is Class D.
And we have seen that the difference between the unicast, that the multicast that that when you put
that IP for unicast, that's for single machine while on multicast, you assign it for a group of machines.
All right.
Now, the last thing that we shared is that it's always safe to use the 239.0.00 and the 272255255255
because that is reserved by IANA for us to use it and multicast.
So this is all about the layer three.
So now we understand it.
Let's see now about the layer two, which is the MAC address or what is the MAC address that is being
used on the multicast now on layer two iota has allocated for layer two multicast others a ranch.
Also for layer two, they have allocated a rush.
The rush starts from
010058000000.
So that's a mac address from this rush.
2010057f, f, f f.
All right, so anything between this range, then this is allocated for the letter to a multicast.
This will leave us 23 bits available to be used.
A multicast group idea.
All right.
To see what we do.
The lab, once we use multicast, we see that the the layer two will be shown up from this right from
here to here.
So what does it mean?
Bottom line, whatever.
You see a mac address going to a destination and starting with 010054, which is you can see that is
here.
This is here.
So why don't you see something starting from the 01005 that no, that that is multicast layer two other
thing.
All right.
So again, remember, that is for the destination.
So now we understand about the nature of layer two on the multicast and the upcoming section.
I have to start there working a little bit with the labs.
So we have to prepare our thick routers to be able to do the lab.
So we need to take the package for multicast and put it on the roster because that Ultra normally does
not have the multicast package enabled by default that we have to start playing with the lab.
So I hope that this lecture was informative for you and also incoming lecture.