Networking - Subnetting - Discussion

Discussion Forum : Subnetting - Subnetting (Q.No. 13)
You have a network with a subnet of Which is the valid host address?
Answer: Option
A Class B network ID with a /22 mask is, with a block size of 4 in the third octet. The network address in the question is in subnet with a broadcast address of Only option E even has the correct subnet mask listed, and is a valid host.
13 comments Page 1 of 2.

Mtk said:   9 years ago
I couldn't understand how did the /22 mask could have block size of 4?

Pruthvi said:   8 years ago
11111111.11111111.1 1 1 1 1 {1} 0 0.00000000/22

128 64 32 16 8 {4} 2 1

Here the host and network parts are separated at 4. So the block size is 4. This is a simple trick.

Haya said:   7 years ago
Why option A is not correct?

It is also a valid host. Because range is in between to

Subhankar said:   7 years ago
Please describe why A is not the correct answer?

Sechonge said:   7 years ago
We know the bi borrowed id 6, ie 11111100 = 252 and we deal with N.N.H.H.

That's why the answer is D.

Nitz said:   6 years ago
Hi, I can not understand how they got it, Can anyone explain me in detail?

Taran said:   6 years ago
Hi Guys!

We have first 6 on-bits so after calculating the values.
128 + 64 + 32 + 16 + 8 + 4 = 252, we get sum of on-bit value.

Block size = 256 - Sum of on bit value.

256 - 252 = 4,
The block size is 4.

Subnets in the network -------- and so on up to

So to here some of you confused that why A is not correct the reason behind it is
that if you select A, as you answer then you are Host bits are showing as network bits bcoz we have an ip of B class and in B class we deal with N.N.H.H, so we are not selecting A as the correct answer due to the wrong Subnet.

D is dealing with class B Subnet.
(172. 16 . 18 . 255)
(255. 255. 252. 0 )
( N . N . H . H )

K.madhusudan reddy said:   6 years ago
Can you give the proper explanation?

Taran said:   6 years ago

D is the right answer bcoz of it's subnet.
class B subnet is always N:N:H:H bits. is also in between the correct range.
A option comes under the C Class subnet tata's why we choose D as the correct answer.

Monty said:   5 years ago
According to the question, this is given but while solving u said in question is used which makes only option D as a correct answer but as per real question, both A & D can be right.

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