The Internet provider owns the address space 200.25.0.0/16 .
To issue addresses to customers, the provider uses part of its address 200.25.0.0/20 .

Using CIDR prefix technology, divide this address space into 4 parts (4 organizations):

  1. Organization A is half the address.
  2. Organization B - 1/4 of the addresses.
  3. Organizations C and D - 1/8 of the addresses.

It is closed due to the fact that the essence of the question is unclear by the participants pavel , aleksandr barakin , ermak0ff , user194374, Denis Bubnov 17 Feb '17 at 6:12 .

Try to write more detailed questions. To get an answer, explain what exactly you see the problem, how to reproduce it, what you want to get as a result, etc. Give an example that clearly demonstrates the problem. If the question can be reformulated according to the rules set out in the certificate , edit it .

  • one
    Live broadcast from the exam? - vp_arth
  • Not. This dz. I can not understand the condition. - Oleg Ovcharenko
  • one
    What is there to understand? divided 200.25.25.0 / 20 into 4 subnets: 21, 22 and two 23. - Akina
  • Well, at least you would not be too lazy to reformulate the whole d / z so that it would have an imperative (“divide”). - VladD

1 answer 1

A network of 200.25.0.0/20 means having 32-20=12 bits per address.
Accordingly, all network addresses: 200.25.0-15.0-255

Select 1/2 for A: 0-7.0-255
Select 1/4 for B: 8-11.0-255
Select 1/8 for C: 12-13.0-255
Select 1/8 for D: 14-15.0-255

In the bit representation, it will look like:

  ....|........ A 0***|******** - 0.0/21 B 10**|******** - 8.0/22 C 110*|******** - 12.0/23 D 111*|******** - 14.0/23