Why is this the best subnet address to use?

[HungryHouse]

Hey all,
I'm a bit stumped at a practice question on some study material I am working on. Here goes:

new subnet with 12 host has been added to the network.
As the network administrator, you will decide which IP subnet address range is best. Which of the following provides enough useable address while wasting the fewest?
A)192.168.10.96/29
B)192.168.10.80/28
C)192.168.10.96/28
D)192.168.10.80/29

Its obvious that the /28 is the correct mask, however, which is a better choice... the .80 or the .96?
You may only choose one answer. Does it really matter as they both use two network bits, and same# of hostbits?
Let me know your thoughts guys and gals.

 

[CiscoGuy33]

HungryHouse,

It appears you are right and with what you have - no way to tell why B or C is better answer.

Where did you get the practice questions?

With a /28 you have a subnet mask of 255.255.255.240 or a range of 16, so far B and C are right, next the subnets are 0, 16, 32, 48, 64, 80, 96, 112...... both B and C are subnets! So both are correct!!!

I think that someone goofed on the question and copied something wrong, normally you would see this and C would be 192.168.10.88/28 which would make it a node and not a subnet!!!

Then you would have only one right answer - my bet is that the answers were listed incorrectly!!!

Where did you get the question?



E.A. Broda
CCNA, CCDA, CCAI, Network +

 

[burtsbees]

What answer and explanation did the study material give???

Burt

 

[HungryHouse]

They believe answer was (C) .96.
Perhaps B is a typo afterall. You just confirmed it for me guys.
Thanks very much!
HH

 

[burtsbees]

What is their explanation???

/

 

[HungryHouse]

They explain the same thing as you'd expect - # of hosts, etc, but no mention of the specifity of .96 over .80, as .80 could've has the same explanation.
wierd!
Just wanted some other pairs of eyes in case I was missing anything..thanks all.

 

[burtsbees]

Got it. Now just tell us where you got the practice questions...por favor...

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