Question

Suppose you are an ISP that owns a / 22 IPv4 address block. Can you accommodate requests from six customers who need addresses for 9, 15, 20, 41, 128, and 260 computers, respectively? If so, how? If not, explain why.

Answer 1

Answer:

It is not possible.

Explanation:

In this example, we need to accommodate 473 computers for six clients that are 473 IP addresses.

For this request just we have /22 IPv4 address blocks, this mean

22 red bits 11111111111111111111110000000000 <--- 10 host bits

We must increase red bits to 25, we need these 3 bits to create 6 sub red, in this case, 2^3 = 8 sub red.

Why did we ask 3 bits? Because if we ask only 2, 2^2 = 4, and we need 6 sub red.

25 red bits 11111111111111111111111110000000 7 host bits

In this case, we need more than 260 computers, but just we have 7 bits, this means.

2^7 = 128 and just one customer needs 260, for that is impossible.