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BOSON Question

jude56gjude56g Member Posts: 107 ■■■□□□□□□□
Here is a question I came across today on a practice exam; either I don't fully understand the concept or the question is wrong (I'm guessing its my understanding).

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

These are the possible answers.


172.16.152.128/28
172.16.144.0/28
172.16.180.0/28
172.16.124.0/28
172.16.164.160/28

By my math, the summary route includes this range:
172.16.128.0 – 172.16.159.255. With that being said, wouldn't all 5 subnets be exclusive of the summary route?

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    RakuraiRakurai Member Posts: 84 ■■■□□□□□□□
    There are 3 correct answers.
    172.16.180.0/28
    172.16.124.0/28
    172.16.164.160/26

    Unless I misread something in their too..... I've seen some weird questions though too. What was the correct answer that it showed?
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    jude56gjude56g Member Posts: 107 ■■■□□□□□□□
    Rakurai wrote: »
    There are 3 correct answers.
    172.16.180.0/28
    172.16.124.0/28
    172.16.164.160/26

    Unless I misread something in their too..... I've seen some weird questions though too. What was the correct answer that it showed?

    Those are the 3 correct answers. Can you shed some light on why??
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    RakuraiRakurai Member Posts: 84 ■■■□□□□□□□
    The summarized route will include the IP addresses from 172.16.128.0 through 172.16.159.255. The IP ranges 172.16.152.128/28 and 172.16.144.0/28 fall in that range of 172.16.128.0 - 172.16.159.255. The 172.16.180.0/28 and 172.16.164.160/28 are both above the end of the summarized route, and 172.16.124.0/28 is under the 172.16.128.0, which is the start of the summarized route.
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    jude56gjude56g Member Posts: 107 ■■■□□□□□□□
    Rakurai wrote: »
    The summarized route will include the IP addresses from 172.16.128.0 through 172.16.159.255. The IP ranges 172.16.152.128/28 and 172.16.144.0/28 fall in that range of 172.16.128.0 - 172.16.159.255. The 172.16.180.0/28 and 172.16.164.160/28 are both above the end of the summarized route, and 172.16.124.0/28 is under the 172.16.128.0, which is the start of the summarized route.[./QUOTE]

    Ok, duh! I'm am idiot. My math was right, and I understand the concept; I simply misread the third octet.

    Thanks!!!
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    DANMOH009DANMOH009 Member Posts: 241
    Hahaha I just spent about 15 minutes reading this and missed it! even with you pointing the answers out, Duh!!!! to me to.

    Oh well more practice needed i guess.
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