Question

(CIDR)

Summarize the following range of IP addresses by ensuring that the summaries do not include any unnecessary addresses. Explain clearly how you arrive at the solution showing all relevant steps. 160.25.30.0/24 160.25.31.0/24 160.25.32.0/24 160.25.33.0/24 160.25.34.0/24 160.25.35.0/24 160.25.36.0/24 160.25.37.0/24 160.25.38.0/24 160.25.39.0/24 160.25.40.0/24

Answer 1

First, we check that if the IP ranges are contiguous or not. In our case, it is contiguous as the 3rd octet of each range goes as 30, 31, 32, 33,...........,40.

Now we calculate the size of each IP range and they should be equal also.

As there is /24 so, the number of bits used for hosts in each IP range is 32-24 = 8

Therefore, the size of each IP range is 2⁸ = 256.

Now as there is a total of 11 IP ranges so, the total size of the summarized IP range will be = 11*256 = 2816.

Now as the size has to power of 2 so, the nearest number is 4096 or 2¹². Therefore, the number of bits needed in the host part of the summarized IP range is 12 and the rest bit i.e. 32-12 = 20 bits will be used for network part.

So, the summarized IP range is 160.25.30.0/20.