In the previous video, we already determine the best prefix and the IP range we will use. 2
We agreed we will use 10.10.10.0/27. 3
Next in this video we are going to calculate the total IP and subnetmask. 4
The total IP is 2 to the power of 32 minus by 27. 5
32 minus by 27 is 5, and 2 to the power of 5 is 32. 6
So the total ip for prefix /27 is 32. 7
Next let’s calculate the subnetmask. 8
The formula is 256 minus by total ip, and the total ip is 32. 9
256 minus by 32. 10
The result is 224. 11
So the subnetmask is 255.255.255.224. 12
Okay we have done with total IP and subntmask. 13
Now let’s calculate the network ip and broadcast ip. 14
Remember that network ip is always started with 0. 15
The network for the next block subnet is 0 plus by the total ip, which is 32. 16
The result is 32. 17
The next block subnet, 32 plus by total ip again, the result is 64. 18
Next block subnet, 64 plus by total ip again, the result is 96. 19
Next block subnet, 96 plus by total ip again, the result is 128. 20
Next block subnet, 128 plus by total ip again, the result is 160, 160 plus by total ip again, 21
the result is 192, 192 plus by total ip again, the result is 224, and so on, until we reach 256 22
Actually we don’t need to calculate until 256, but for learning, we are going to calculate 23
until 256. 24
Here 224 plus by total ip again, 32, the result is 256. 25
Okay here we already reach 256. 26
We can stop here. 27
Next let’s calculate the broadcast ip. 32 minus by 1 is 31. 28
Here is 63 because 64 minus by 1. 29
Here 127, here 159, here 191, here 223, and here 255. 30
Okay, so this is the block subnet for /27. 31
Here we have block subnet 1, block subnet 2, block subnet 3, block subnet 4, block subnet 5 32
block subnet 6, block subnet 7, and block subnet 8. 33
So we have 8 block subnet here. 34
We are free to use which block subnet we want. 35
Let’s say we are going to use the first block subnet. 36
So the network is 10.10.10.0, the third first number is not change and the last number is 37
the result of our calculation. 38
And then the broadcast is 10.10.10.31. 39
Remember that network ip and broadcast ip will never can be used. 40
So the ip that we can use is after network ip until before broadcast ip. 41
So the ip range is 10.10.10.1, after 0 is 1, until 10.10.10.30, before 31 is 30. 42
Okay, so for these 15 pc, we are free to use the ip from range 10.10.10.1 until 10.10.10.30. 43
Okay I think enough for this video, in the next video, we are going to practice using 44
packet tracer. 45
Thankyou for watching and see you on the next video!