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Subnetting question...

binaryhatbinaryhat Member Posts: 129
in CCNA & CCENT
Question: Which subnet does host 172.25.202.3 255.255.255.240 belong to?

Block size is 16, 256-240
3rd octet

0
16
32
48
64
80
96
112
128
144
160
176
192
208

Answer: 172.25.202.0

It should be 172.25.192.0, yes?
Currently working on:
ICND1 - TBD
Book: CCENT/CCNA ICND1 100-101 Official Cert Guide
Equipment: Packet Tracer, GNS3
Supplement Material: Youtube, Google, Boson ExamSim-Max, CBTNuggets
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    blatiniblatini Member Posts: 285
    It's fourth octet. First through third are already maxed at 255. So it would be 172.25.202.0 network with 172.25.202.15 broadcast.
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    binaryhatbinaryhat Member Posts: 129
    Ahhh...mental block. I see now.
    Currently working on:
    ICND1 - TBD
    Book: CCENT/CCNA ICND1 100-101 Official Cert Guide
    Equipment: Packet Tracer, GNS3
    Supplement Material: Youtube, Google, Boson ExamSim-Max, CBTNuggets
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    NetworkVeteranNetworkVeteran Member Posts: 2,338 ■■■■■■■■□□
    Good explanation, blatini.
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    Ollie1211Ollie1211 Registered Users Posts: 2 ■□□□□□□□□□
    Hi I'm not sure if this is where I post this but, I have an example question for an exam, and I was hoping someone could explain the answer to me. If the ip address on my machine is 192.168.1.73 and the subnet mask is 255.255.255.192, which of the following devices are also on my IP subnet?
    i. 192.168.1.64
    ii. 192.168.1.65
    iii. 192.168.1.63
    iv. 192.168.1.73
    are they all on my IP subnet seen as the first 3 octets are the same. I'm just confused with this. Thanks for any help.
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    blatiniblatini Member Posts: 285
    Is that a real question? Why would the original host also be a part of the question? I suppose the answer is ii and iv. You are looking at the fourth octet and have 2 subnet bits and 6 host bits. 192.168.1.0, 192.168.1.64, 192.168.1.128.... etc.

    Only reason I ask if it's real is because there's a chance you mistyped and the answer could actually be completely different... not trying to be condescending or anything.
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    Ollie1211Ollie1211 Registered Users Posts: 2 ■□□□□□□□□□
    Sorry about that, it should of been for iv. 192.168.1.173
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    alphagolfalphagolf Registered Users Posts: 3 ■□□□□□□□□□
    IP:192.168.1.73
    Mask: 255.255.255.192

    Meaning you've got a 64 block in the 4th octet.

    Subnets as blatini pointed out are as follows:
    192.168.1.0
    192.168.1.64
    192.168.1.128
    etc.

    If you're not sure why we're counting up in 64's you may want to visit some of the other subnetting topics. I learnt how to subnet from this thread in particular: http://www.techexams.net/forums/ccna-ccent/38772-subnetting-made-easy.html

    Your device of 192.168.1.73 is in between the x.64 x.128 subnets.

    So, as blatini mentioned your answers are x.65 and x.63.

    192.168.1.64 is NOT included because it's the subnet ID and is not associated with an actual device.

    HTH =)
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