Solved Example on IP4

An organization is granted a block of addresses with the beginning address 14.24.74.0/24.  The organization needs to have 3 subblocks of addresses to use in its three subnets  : one subblock of 10 addresses , one subblock of 60 addresses ,and one subblock of 120 addresses .Design  the subblocks??

Answer

There are 232 -24 =256 addresses in this block. the first address is 14.24.74.0/24; The last address is 14.24.74.255/24.

To satisfy the third requirment ,we assign addresses to subblocks, starting with the the largest and ending with the smallest one.

1) The number of addresses in the largest subblock ,which requires 120 addresses, is not power of 2, we allocate 128 addresses .The subnet mask for this subnet can be found as  32 -log2128 =25. The first address in this block is 14.24.74.0/25 ; the last address is 14.24.74.127/25.

2)The number of addresses in the second largest subblock , which requires 60 addresses , is not a power of 2 either, we allocate 64 addresses .The subnet mask for this subnet can be found as 32 - log264 = 26.The first address in this block is 14.24.74.128/26;The last address is 14.24.74.191/26

3) The number of addresses in the smallest subblock ,which requires 10 addresses, is not a power of 2 either.we allocate 16 addresses.The subnet mask for this subnet can be found as 32-log216 = 28. The first address in this block is 14.24.74.192/28; The last address is 14.24.74.207/28

1Comment
Kinza Iqbal Khan @kinzajadoon31
11 Feb 2021 01:37 pm

if we have /32 then what will our outcome?