Little help needed.

knownhero

In the MCSA press book I have come across this question:

Which subnet mask would you assign to the new server?

Subnet 1: Exisiting computers

10.2.12.1
10.2.41.23
10.2.41.100
10.2.41.101

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A. 255.0.0.0 /8
B. 255.255.0.0 /16
C. 255.255.255.0 /24

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I actually dont understand this question at all. (Though I just guessed /16) could someone explain as it why? I have a rough understanding of subnetting but this question just blew me away I had no idea how to work it out.

Cheers

knownhero

Nevermind figured it out myself.

They only have 10.2 in common so 255.255 is fine.

RobertKaucher

It is giving you a group of network addresses, all of which are on the same sub-network. You need to be able to determine just from looking at them which subnet maks you would use. The answer is most probably B, although I would like to see the exact wording of the question.

The reason I say B is because the question used the temr "subnet." This tells me it is probably NOT a standard class A network using a 255.0.0.0 subnet mask. Since all of the network addresses share the 10.2.x.x patter it is safe to assume they need a /16 subnet mask.

RobertKaucher

Not allowed to figure it before I can finish my post! Glad you got it.

knownhero

RobertKaucher wrote: »

It is giving you a group of network addresses, all of which are on the same sub-network. You need to be able to determine just from looking at them which subnet maks you would use. The answer is most probably B, although I would like to see the exact wording of the question.

The reason I say B is because the question used the temr "subnet." This tells me it is probably NOT a standard class A network using a 255.0.0.0 subnet mask. Since all of the network addresses share the 10.2.x.x patter it is safe to assume they need a /16 subnet mask.

Hey Robert and thanks for the reply.

How I wrote the question is how it is in the book When I went back to look at it I noticed the 10.2.x.x and thought that it would be a /16 also. Again thanks!