A network technician is creating a new subnet for 488 host machines. The technician is told to use a class B address scheme when making the subnet and is instructed to leave as much room as possible for additional subnets of the same size. Which of the following subnets would fulfill these requirements?
A. 10.5.4.0/22
B. 10,233.2.0/23
C. 172.16.0.0/22
D. 172.18.0.0/23
E. 192 168.25.0/24
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Class B scheme means 128-191 for first octet (narrows to answers C or D with 172) and first 16 bits are the network. /23 mask means the next 7 bits (16 + 7 = 23) are for subnets (2^7 = 128 subnets). Leaving the final 9 bits for usable IPs per subnet = 2^9 = 512. Question asks to “leave as much room as possible for more subnets of the same size” (the key here is it’s asking for more subnets, not more usable IPs) and a /23 mask allows *128* subnets and 512 IPs per (which still accommodates the 488 hosts requirement) while a /22 mask would only allow *64* subnets with 1024 IPs per. Thus, Answer D seems correct.
why no/22 will give you 1022 host? can someone help me to explain for this question pls? I have been tried so hard to answer this, why the answer not c ?
I got D for the answer
That’s a tricky question.
leave as much room as possible for additional subnets “of the same size”
A network technician is creating a new subnet for “488 host” machines.
D seems to be correct. We will get 128 subnets with 512 hosts with /23 (512 is almost the same size as 488)
Hint Class B
128-191
eliminates options A, B and E
The quickest way to get to know the answer for the exam is to take 32 away from the number after the slash. For e.g. 32 – 23 = 9. We know the Class B goes from 128 to 191. We know it is either going to be C and D. So the BEST possible answer is C.
The quickest way to get to know the answer for the exam is to take 32 away from the number after the slash. For e.g. 32 – 23 = 9. We know the Class B goes from 128 to 191. We know it is either going to be C and D. So the BEST possible answer is D.
if you wanted more subnets, woudln’t you use a /22? 172.16.0.0
No, /22 will give you 1022 host, while /23 will give you 510 host, therefore /23 will leave as much room as possible.