Help with manual summarization question required.

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Can anyone explain the answer to this Boson ICND2 question, the question
states:

An engineer has implemented manual route summarisation with EIGRP in which
the one summary route is 172.16.128.0/19. Another engineer needs to install
a new VLAN & subnet. The following are some of the subnet numbers being
considered by the second engineer for the new subnet. Which one lists a
subnet that would not be represented as part of the existing summary route?

A. 172.16.144.0/28

B. 172.16.164.160/28

C. 172.16.180.0/28

D. 172.16.124.0/28

E. 172.16.152.128/28

The answers are B & C but D also does not overlap? The explanation states
that the summary route represents the following range of numbers:

172.16.128.0 - 172.16.159.255

The answers represent:

172.16.144.0/28: 172.16.144.0 - 172.16.144.15

172.16.152.128/28: 172.16.152.128 - 172.16.152.143

172.16.164.160/28: 172.16.164.160 - 172.16.164.175

172.16.180.0/28: 172.16.180.0 - 172.16.180.15

172.16.124.0/28: 172.16.124.0 - 172.16.124.15

What am I missing?

Re: Help with manual summarization question required.
you are correct jason ..
/19 --> 32 blocksize ... 172.16.128.0 -- 172.16.159.255

since D is only / 28 --> 16 block size ..  172.16.124.0 -- 172.16.124.15
which does not over lap.

if your book has a website, i'd check there for corrections... it happens
from time to time.. its all good.. you are not crazy ..



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Re: Help with manual summarization question required.

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Thanks for putting my mind at ease, it made no sense to me.

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