# CIDR and Subnetting

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00:02

Well, welcome back to cyber areas. Create a sudden it today we're gonna go over cider and submitting. I'm your instructor. Trendy arrow gladdened begin.

00:12

So you said we're gonna win with cider is And also we're gonna take a look at how to do some basic subject.

00:19

Cider is your classless inter domain routing. So what? This helps ISS

00:24

when you're somewhat classless Networking, right. Imagine the class full networking means you have your network said your B networks. You see networks meaning if you use a network, you have, you know, two million up you dresses for

00:37

that no network, which is, you know, you're probably not waste quite a bit of those I p addresses where, as you know, class see, you only have the ability to put in 254 eyed peas into a network.

00:49

So the way this is represented here was with a slash number notation. That number corresponds to the number of network bits and sudden it bits BB and used for that network. Right for that, Suddenly

01:02

so, slash 24 is a traditional, classy network being it's using 24 bits for the networking portion. There's eight bits for the host portion.

01:11

Right? So that would equate to a sudden that mask up to 55 to 35 to 35 in a Class B network. Thank you. Need you know, 16 bits, So slash 16. Class A is a slash acres. You need eight bids.

01:26

Uh, and the way that these were gonna work. You know, if you add up all eight bits in that octet, you're gonna get to 35 right?

01:34

You got a mirror that this is not supported in rip routing protocols. Right? So rip is a class full networking routing protocol,

01:42

so let's go ahead and move on to a little bit of cider practice. I will give a few seconds deposit and get some No paper and a pen. We'll go ahead and begin.

01:53

All right? Hopefully you guys got this done already. That's good. Go ahead and begin Otherwise. So here. We're gonna go ahead and just do 2 35 So what we need to dio is we need to add up our different bits. Right?

02:08

So we're gonna imagine this first bit here, so I got 1 28 plus 64 is 1 92

02:16

3rd 1 that's gonna be 2 24

02:21

Because this is your 32 place, remember?

02:23

When the next one gets it to 40 for a 16? Well, at 84 to 1,

02:30

which will.

02:31

So let's go ahead and do to 48.

02:36

2 52

02:38

onto what? That's a 5 to 54 then two. Well, 2 55

02:46

Okay,

02:49

2 55 total. Right.

02:51

So what we need, how many bits are we being used here? So this would be a slash eight

02:57

going screen, and we'll move on to the last one, so we know we need so

03:02

we need eight here.

03:06

Eight bits are being used here and eight bits. Are you being used here? So if we go ahead and just begin this with 1 28 we know that only one bit is being here. It used here. So this is gonna be a slash 25

03:19

right?

03:21

Because I always 000000

03:25

Right? Yeah.

03:27

So, essentially, this portion here would be your host.

03:30

Who's bits,

03:32

and this is the last octet. You have your sudden that bit.

03:38

So the last one, I hope you figured it out. We need 30 different bits.

03:43

So I'm gonna go ahead and move, Isn't it decimal? So I know that there's gonna be 2 55 to 55

03:51

too fortified to get us to the nearest classical network.

03:54

So I'm gonna go ahead and do my little thing that you hear networking bits sudden at best host bets.

04:02

So we know that we have 24

04:05

which would leave us with six sub nets and to host, right, because these two together would give you your slash 30.

04:15

So let's go ahead and put these 67 that bits into a for six on your to host bits. Right?

04:23

So essentially, we could just minus three awful of 2 35 because this would be three if you did a one of the one.

04:30

So 40 to 55 minus three would leave us with 2 52

04:36

So that is the last octet of that, son. That mask.

04:42

All right, clear screen. And we will move on here. So subheading, the way that is generally kind of scene is you need thio. It's a determinant based on the host eyepiece that you need, right? So if you have a network that only has 64 devices.

04:59

Then

05:00

you know you base your somewhat off that you don't need a full class C sub net if you need 64 I p addresses, right.

05:06

You actually need a slash 25. Because remember that 64 is being used, but then you need you have to minus two for the usable. See, actually end up with 62 usable I p addresses.

05:18

So the quick way I like to determine my son. That mask. Uh well, use this again. So do the slash 28 up here

05:28

I do my networking, my sudden obits and my host bits. So this would be

05:33

24. This would leave us with four sub nets and four Host that 1234 So 1 28 1 92

05:44

to 24 to 40. Right.

05:47

So here we're going. You know, we got our quick, sudden that mask So to 35 to 55 to 55 to 40.

06:00

And here's how the way that I utilize this last suddenly or this last said not here is so if we did 2 55 minus 2 40

06:10

2 56 apologize. That leaves us with 16 right? We know that our block size that we can utilize for I P addresses is 16. We can hold 69 piece per sub net.

06:21

Right.

06:24

So let's go ahead and move into a slash 22. Here, clear the screen off.

06:28

So slash 22. It gets a little bit different when you get into the class. Be submitting.

06:34

So network suddenly host.

06:39

So we're gonna do first class full 16. 16. It leaves us with this and 10 host bits. Right.

06:46

So we know that. 123456

06:50

No,

06:54

or 5678 Right. These are the last to our tests.

06:58

So let's go ahead and do the last bit. Maybe we could just minus three. So we know that this is a duck to 52. If you do the math of adding up, these or you could just minus three from that there.

07:13

So, you know, whatever, that stupid too.

07:15

So we can kind of do that same trick with a Class B networks to fortify or 2 56 minus 2 52

07:24

Right. That leaves us with

07:26

four. Okay,

07:29

So how that's gonna work is you can actually look at essentially think of it as we have four class C networks that we can utilize, right?

07:36

So I'm just simple 10 1

07:40

you know, 00

07:43

through 10

07:45

1.3 to 55. That's our actual eyepiece base that we can utilize for that slash 22. Right?

07:56

Because if you think about it, we're essentially using three

08:00

different, because then you have your 12 and your three networks, right?

08:05

They're using four different classy network. So you can still kind of use that trick. And it would be the same thing if you were to suddenly a class A network. You could you could essentially say you had this many class B submits to utilize.

08:20

Um,

08:20

so you have, you know, 10. 24

08:24

i p addresses. Because if you do to 55 by four class sees no,

08:31

10 24

08:33

the other way that you can do that here If you need to determine if you have Ah, this is one way. Actually utilize a calculator. Um,

08:41

if you look at this year, you have 10 sudden at best, Anyone who determined real quickly how many

08:46

I please you. Have you can do 10 or to raise 2 10 Remember, because you can use those basic. There's a base to system. And that would give you 10. 24 as well. Right?

09:00

I guess this would be to 56.

09:03

Let's go ahead and clear the screen off here. Let's go down to this bottom portion. Determined subject mass needed for the I. P is needed.

09:11

So one thing we can do here

09:13

due to 56

09:16

minus 66

09:18

All right, so that is gonna give us 1 90 right? So when you look at what we can utilize off, that's great. You essentially saying that your sudden that mask

09:28

needs to be

09:31

essentially below this number, Right?

09:33

So if we do the 1st 1 of 1 28

09:37

that's below. We can utilize that we can use one sudden. It bit

09:41

s o. The next one will be 64 which would equate to 1 92 So that would be about right? We can't utilize that. So then you're so that would be

09:52

this far.

09:54

So essentially saying that the last act Tet are saying to 55 to 45 to 55 that 1 28 or a slash 25. Right, Because you're using that one extra sudden up it.

10:09

So again, that would look like Network 24 Sub net one host seven.

10:18

All right. Hey, let's move on to 2112.

10:22

So let's take a look here. Here's where we're really going to want to utilize some actual calculator math unless you're really good at this stuff.

10:31

So let's look at what we're gonna utilize here,

10:37

because obviously we can't do our 10 24 trick. Here are the 256 minus the peace space, because we're gonna have to actually tap into the Class B network.

10:48

So let's try and figure this out here. The way I like to do it is kind of the lazy way is we know that

10:56

10 suddenly bits could just learn is 10 24.

11:00

So if we give it one extra so 11 would be

11:03

2048. Okay, we don't have enough still so 12

11:09

give us 40 96 minus two. Of course.

11:13

So we need to use 12

11:15

for the host.

11:18

I wish it if we d'oh in order here,

11:24

do 16. Because we're gonna use a Class B network for that.

11:28

Which means we had to borrow four bids for this. Which means we use four bits for the sudden mask.

11:35

So let's go ahead and do 2 55 to 55 because we know that is a Class B network right here.

11:43

And then we need to figure out for sudden it's a 1234

11:46

1234 There we go. So 1 28

11:50

and I'm just gonna go ahead and add these up. 64 32 16. So

11:56

1 92

12:00

to 24 watts, bed to 24 add that last 16 in there.

12:07

What gives the 2 40 So here would be our protector. Zero.

12:11

And this would be remember, So add these two up, so this would be a slash 20 network.

12:24

All right, so we're gonna go ahead and move on to the quiz here. Hopefully you remember. What is the subject mask you need for a network that requires 254 I p addresses?

12:35

Give you second deposit

12:39

already? Hopefully everyone got

12:41

that. You are going to require just a classy network, right? You just need

12:46

slash 24 because you need eight bits for 2 54 addresses that will give you a perfect amount. Now, again, that doesn't give you any room for expansion because you're going to utilize every I p address.

12:58

But that will work, right?

13:03

All right. In today's video, we went over what cider is. And we talked about how to utilize that Byner math to determine our sub net sizes.

13:11

Don't thank you for watching today's video, and I look forward to a senior next one,

13:16

huh?

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