00:04

next, I'm going to keep my I P address the same, but I'm going to change my mass to a slash 30.

00:12

So if I were to ask you,

00:15

what would the Mass look like? Indicted decimal course Last 30 is more than 24 bits. So you know the 1st 3 octet CE, which is eight bits, eight bits and eight bits. The mask is going to be 255 not

00:38

So I'm going to draw out the last octet slashed 31 2345667812

00:56

So the 1st 2nd and third akademik 24 bits eight plus eight plus eight is 24.

01:02

I have to get to the number 30

01:10

1 28 plus 64 plus 32 plus 16 plus eight before gives me 2 52 so the mass would become 255255255.25

01:26

Shoot. Now, if you notice the value of the last bit turned on here

01:34

started 1 51 01 45.0 slash 30

01:42

My next street over or my next network starts at

01:46

1 51 01 45.4 its last 30. My next one will start at 1 51 01 45 dot Add 4 to 4. You get eight. I'm just making jumps of four.

02:04

My next one would start at 1 51 01 45.12 slash 30.

02:12

The valid addresses over here and the first network would be 0.1 and not two

02:17

0.3 would be my broadcast

02:22

again. In the next street over

02:23

my house numbers would be 0.5 and 0.6

02:29

0.7 again would be broadcast

02:35

my next street over. My valid addresses are gonna be 0.9 and dot Tenn 0.0.11 would be my broadcast.

02:45

The point I'm getting at is that with a slashed 30 mask,

02:50

you only get two addresses.

02:52

So a slashed 30 mask or 255255255 to 5 to mask should always be used

03:00

over point to point links.

03:02

So if you have rather one on this side and router to on this side.

03:07

One address goes here on one address goes here so over point to point lengths that could be on the exam. You always use this last 30 or a 2 52 masked. Otherwise you're wasting addresses.

03:20

You only need to address his one on each side. Any other mass like a slash 29 mask would yield six addresses and you're wasting for.

03:29

And as you guys notice, I'm not even playing with I p. I'm simply playing with the mask.

03:42

64 God zero. My question to you guys are question could be What is the valid host range for this network?

03:51

Well, let's figure it out

03:53

again. I'm going to take the sub net mass, which is slash 19 and break it down into binary.

04:00

So this time I'll do the whole thing.

04:26

So are we working in the first octet? Second octet, 3rd October four talked yet. Let's find out. 19 bits turned on

04:32

123456789 10 11 12 13 14 15 16 17 18 19. I'm working in the third octet. The rest of the bits

04:46

What is the value of the last bit turned on? Let's find out.

05:00

So the value of the last bit turned on

05:06

So we have found out that the value of the last bit turned on is 32

05:11

1 28 plus 64 plus 32 is to 24. So this is to 24

05:17

the first octet. Everything's on. So it is 255

05:21

Second doctor is 255 3rd octet is to 24 the last octet. Everything is off, so it's simply zero.

05:30

So I'm gonna go ahead and erase this because they need the space.

05:33

Just remember that the value of the last bit turned on was 32. So the mask will be

05:42

255 indicted decimal. It would be to 55255 to 24.0 You start at 1 50

06:00

What was the value of the last bit turned on?

06:05

and I'm looking for the 64 network. So my first street started at 1 51 a 10.0

06:14

My next street will start at

06:16

I should write this a little bit higher. So my first restarted at 1 51 a 10.0 slash 19

06:27

My next network or street

06:29

is we're working in the terror doctor, remember?

06:32

1 51 01 And I simply add 32. Since the value off the last bit turned on was 32

06:46

my next network would be

06:59

My next network would be 1 50

07:02

101 96. I just simply at 32 to 64 to yield 96

07:14

So I had asked, What is the valid host range for this network?

07:19

the first address would be

07:28

The last possible address

07:30

for this street would be one before the next street. Since the next street is starts at 96 it would be 95 dot

07:48

would be my last valid address. 95 255 as always, being my

07:56

broadcast. So my valid range would be 64.1

08:00

through 95.254 Not hard, guys. Uh, as long as you remember the rule,

08:07

you look at the value of the last of it turned on.

08:11

And then that gives you the block size. Then you start a zero in that op ed and keep adding that number until you get to your element network that you're trying to find the range for.

08:20

Okay, I'm gonna go ahead and raise the board. We will do one more

08:24

example question, and then we will move on