next, I'm going to keep my I P address the same, but I'm going to change my mass to a slash 30.
So if I were to ask you,
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
So I'm going to draw out the last octet slashed 31 2345667812
So the 1st 2nd and third akademik 24 bits eight plus eight plus eight is 24.
I have to get to the number 30
1 28 plus 64 plus 32 plus 16 plus eight before gives me 2 52 so the mass would become 255255255.25
Shoot. Now, if you notice the value of the last bit turned on here
started 1 51 01 45.0 slash 30
My next street over or my next network starts at
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.
My next one would start at 1 51 01 45.12 slash 30.
The valid addresses over here and the first network would be 0.1 and not two
0.3 would be my broadcast
again. In the next street over
my house numbers would be 0.5 and 0.6
0.7 again would be broadcast
my next street over. My valid addresses are gonna be 0.9 and dot Tenn 0.0.11 would be my broadcast.
The point I'm getting at is that with a slashed 30 mask,
you only get two addresses.
So a slashed 30 mask or 255255255 to 5 to mask should always be used
over point to point links.
So if you have rather one on this side and router to on this side.
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.
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.
And as you guys notice, I'm not even playing with I p. I'm simply playing with the mask.
64 God zero. My question to you guys are question could be What is the valid host range for this network?
Well, let's figure it out
again. I'm going to take the sub net mass, which is slash 19 and break it down into binary.
So this time I'll do the whole thing.
So are we working in the first octet? Second octet, 3rd October four talked yet. Let's find out. 19 bits turned on
123456789 10 11 12 13 14 15 16 17 18 19. I'm working in the third octet. The rest of the bits
What is the value of the last bit turned on? Let's find out.
So the value of the last bit turned on
So we have found out that the value of the last bit turned on is 32
1 28 plus 64 plus 32 is to 24. So this is to 24
the first octet. Everything's on. So it is 255
Second doctor is 255 3rd octet is to 24 the last octet. Everything is off, so it's simply zero.
So I'm gonna go ahead and erase this because they need the space.
Just remember that the value of the last bit turned on was 32. So the mask will be
255 indicted decimal. It would be to 55255 to 24.0 You start at 1 50
What was the value of the last bit turned on?
and I'm looking for the 64 network. So my first street started at 1 51 a 10.0
My next street will start at
I should write this a little bit higher. So my first restarted at 1 51 a 10.0 slash 19
My next network or street
is we're working in the terror doctor, remember?
1 51 01 And I simply add 32. Since the value off the last bit turned on was 32
my next network would be
My next network would be 1 50
101 96. I just simply at 32 to 64 to yield 96
So I had asked, What is the valid host range for this network?
the first address would be
The last possible address
for this street would be one before the next street. Since the next street is starts at 96 it would be 95 dot
would be my last valid address. 95 255 as always, being my
broadcast. So my valid range would be 64.1
through 95.254 Not hard, guys. Uh, as long as you remember the rule,
you look at the value of the last of it turned on.
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.
Okay, I'm gonna go ahead and raise the board. We will do one more
example question, and then we will move on