subneting question... please clarify

[banajahms]

Hello guys,

I have recently encountered a subneting question which I need some explanation for. The question says:

You are attempting to properly subnet the IP space of one of the Testking location.

For the network “200.10.10.0” there is a need for 3 loopback interfaces, 2 point to

point links, one Ethernet with 50 stations and one Ethernet with 96 stations. What

option below would be the most efficient (for saving IP addresses)?

I answered with the follwing:

200.10.10.193/29, 200.10.10.194/29, 200.10.10.194/29

200.10.10.200/30, 200.10.10.204/30

200.10.10.128/26, 200.10.10.0/25

The correct answer for the question was

200.10.10.1/32, 200.10.10.2/32, 200.10.10.3/32

200.10.10.4/30, 200.10.10.8/30

200.10.10.64/26, 200.10.10.128/25

Even though the answer I provided wasn’t posted as a choice for the question, I still have some enquiries; Is my answer less efficient than the second or are they both ok? If not, why? Also, I can see that my selection for the loopback addresses isn’t as efficient but is it that big of a deal?

Thanks

CHEERS

[pkhatri]

Hi,

Your answer is perfectly alright. Given the requirements, you can answer the question in a number of ways:

- the /25 can be either 200.10.10.0/25 or 200.10.10.128/25

- the /26 can be either 200.10.10.0/26, 200.10.10.64/26, 200.10.10.128/26, 200.10.10.192/26 (depending on which of the above /25s you use)

In a multiple choice scenario, you will only have one correct answer (or maybe multiple ones - the question will tell you how many).

Your choice of loopback addresses is no less efficient than given in the answer - it should work just as well.

Hope that helps - pls rate the post if it does.

Paresh