Misprint on page 169 Q18. Subnetting

[mid4]

The question ask:

You have a network with a subnet of 172.16.17.0/22. Which is the valid host address?

A. 172.16.17.1 255.255.255.252
B. 172.16.0.1 255.255.240.0
C. 172.16.20.1 255.255.254.0
D. 172.16.16.1 255.255.255.240
E. 172.16.18.255 255.255.252.0
F. 172.16.0.1 255.255.255.0

/22 is Block 4 increment in the third octet and a mask of 252

Only possible answer can be E. But There is no .17.0 subnet and also if answer E was correct then the valid host would be 172.16.19.254

0.0 - 3.255
4.0 - 7.255
8.0 - .12.55
12.0 - 15.255
16.0 - 19.255
20.0 - 23.255

Someone please advice.

[Lion66six]

The question ask:

You have a network with a subnet of 172.16.17.0/22. Which is the valid host address?

A. 172.16.17.1 255.255.255.252
B. 172.16.0.1 255.255.240.0
C. 172.16.20.1 255.255.254.0
D. 172.16.16.1 255.255.255.240
E. 172.16.18.255 255.255.252.0
F. 172.16.0.1 255.255.255.0

/22 is Block 4 increment in the third octet and a mask of 252

Only possible answer can be E. But There is no .17.0 subnet and also if answer E was correct then the valid host would be 172.16.19.254

0.0 - 3.255
4.0 - 7.255
8.0 - .12.55
12.0 - 15.255
16.0 - 19.255
20.0 - 23.255

Someone please advice.

This one is tricky, and that is a good thing in my opinion. You have seen that the block size is 4, therefore technically there is no .17 subnet. The IP range would would start at 172.16.16.0 to 172.16.19.255 (Not including the subnet and the broadcast). As a result the answer is E.

Perhaps if the words "with a subnet" were to be removed so it read as the following :

You have a network of 172.16.17.0/22 bah bah bah

then things might be a little easier for you to understand. However cisco is good at making you have to think what they are really asking for. Its not always clear in the way they write exam questions.

Anyway my 2cents :-)

[lammle]

Bascially, regardless of how Cisco words their questions (yes, I try and make mine as tricky as theirs), the only valid host to the 172.16.16.0/22 network in that question is E. Yes, it has 172.16.17.0 (which actually is a valid host in itself, isn't it?)
The question isn't bad, nor great, but not technically wrong either.
Hey, don't shoot the messenger. It did make you think, and you do understand subnetting if you were finding this and writing the information out as you did.
Todd Lammle

[mid4]

Now thinking about .17 is a valid host, but its not a subnet.

I only picked E as the mask matched.

Bur if you read the answer is says that question is asking for .16, has there been a misprint in the question?

[lammle]

No, the question is not wrong. That's how Cisco likes to word things, to throw you off base!
Once you figured out the subnet based on the information provided, you knew your valid host range. That's all they were asking you to do - provide a valid host in that subnet, which you had to determine what it was first.
Todd

[mid4]

No, the question is not wrong. That's how Cisco likes to word things, to throw you off base!
Once you figured out the subnet based on the information provided, you knew your valid host range. That's all they were asking you to do - provide a valid host in that subnet, which you had to determine what it was first.
Todd

A valid host on that subnet would be 16.1 - 19.254.
The address (172.16.17.0) in the question falls into that host range, but the subnet is 16.0.

There when is says: You have a network with a subnet of 172.16.17.0/22. Which is the valid host address?

To me it says you have a network which starts at the subnet of 172.16.17.0 and what are the valid host ranges for that network. And its 16.1 - 19.254.

Now answer E. 172.16.18.255 255.255.252.0 is correct due to its mask but the ip address is not in the subnet of 172.16.17.0 as there is no network which starts with that subnet.

Sorry but it does not make scene to me.