0th subnetting

njcowboynjcowboy Member Posts: 42 ■■□□□□□□□□
in CCNA & CCENT
Apparently, from what I am reading, there is some confusion on this.

Most of the test prep questions that I have seen assume that you exclude all 1's and all 0's

Does anyone know cisco's official stance on the exam? or if it varies, will the questions state as such that it includes or excludes all ones and and zeroes???

Here is a sample question from a non-cisco exam prep

The host 213.115.77.0 was subnetted with a /28 subnet.
How many usable subnets and hosts were created as a result?

A. 2 networks with 62 hosts
b. 6 networks with 30 hosts
C. 16 networks with 16 hosts
D. 62 networks with 2 hosts
E 14 networks with 14 hosts
F 16 networks with 14 hosts


Obviously, depending on the inclusion or exclusion of the 0th subnet, the answer could be E or F
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Comments

  • thesemantheseman Member Posts: 230
    With myself never having taken the CCNA, you might want to double check this with others.

    It is assumed that you CAN and should use subnet 0 on the CCNA, unless explicitly instructed to NOT use subnet 0.

    Travis
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  • dtlokeedtlokee Member Posts: 2,378 ■■■■□□□□□□
    theseman wrote:
    With myself never having taken the CCNA, you might want to double check this with others.

    It is assumed that you CAN and should use subnet 0 on the CCNA, unless explicitly instructed to NOT use subnet 0.

    Travis

    Yes that is the assumption (ip subnet-zero is enabled.)

    Now if ip subnet-zero is off (no ip subnet-zero) then don't use the first and last ranges (the all zeros and all ones subnets)
    The only easy day was yesterday!
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  • bighornsheepbighornsheep Member Posts: 1,506
    According to Todd Lammle's latest book for 640-821, Cisco's official expectation for CCNA is that subnet-zero is allowed. Unless if there is specific instructions to not use subnet zero (and subnet 1), you assume it can be used.

    So, the answer is F (or E if you can't use subnet-zero)
    Jack of all trades, master of none
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  • r_durantr_durant Member Posts: 486 ■■■□□□□□□□
    I've read in posts on this site that Cisco will state whether you would use subnet zero or not...

    I don't think they will just leave you hanging like that anyway, with two possible scenarios and two possible answers...

    So you assumptions on the answers would be correct, but I think most people just assume subnet zero...
    CCNA (Expired...), MCSE, CWNA, BSc Computer Science
    Working on renewing CCNA!
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  • dtlokeedtlokee Member Posts: 2,378 ■■■■□□□□□□
    Any questions about subnetting should be obvious what they want.

    It may state that subnet-zero is on or off, the answer choice for one or the other simply wont be there and so on.

    If you know subnetting, then you have nothing to worry about with regards to ip subnet-zero
    The only easy day was yesterday!
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  • njcowboynjcowboy Member Posts: 42 ■■□□□□□□□□
    dtlokee wrote:
    Any questions about subnetting should be obvious what they want.

    It may state that subnet-zero is on or off, the answer choice for one or the other simply wont be there and so on.

    If you know subnetting, then you have nothing to worry about with regards to ip subnet-zero

    Thanks guys.

    Subnetting is not a challenge for me. Thank god.

    Now if I could master WAN connections, I would be golden

    Time to break out a bottle of Sailor Jerry's rum.
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  • NetstudentNetstudent Member Posts: 1,693 ■■■□□□□□□□
    Fifteen men on a dead man's chest
    Yo ho ho and a bottle of rum.

    Drink and the devil had done for the rest
    Yo ho ho and a bottle of rum.

    Good luck mate! icon_lol.gif
    There is no place like 127.0.0.1 BUT 209.62.5.3 is my 127.0.0.1 away from 127.0.0.1!
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  • ITdudeITdude Member Posts: 1,181 ■■■□□□□□□□
    Do they really have cowboys in New Jersey? :) I think maybe someone slipped me some rum. icon_wink.gif


    ditto with what dtlokee said regarding subnet zero.
    I usually hang out on 224.0.0.10 (FF02::A) and 224.0.0.5 (FF02::5) when I'm in a non-proprietary mood.

    __________________________________________
    Simplicity is the ultimate sophistication.
    (Leonardo da Vinci)
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  • njcowboynjcowboy Member Posts: 42 ■■□□□□□□□□
    Netstudent wrote:
    Fifteen men on a dead man's chest
    Yo ho ho and a bottle of rum.

    Drink and the devil had done for the rest
    Yo ho ho and a bottle of rum.

    Good luck mate! icon_lol.gif
    Did you test out today?
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  • r_durantr_durant Member Posts: 486 ■■■□□□□□□□
    I think he has it at 3pm, so he may be intransit...if not there already!!
    CCNA (Expired...), MCSE, CWNA, BSc Computer Science
    Working on renewing CCNA!
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  • njcowboynjcowboy Member Posts: 42 ■■□□□□□□□□
    ITdude wrote:
    Do they really have cowboys in New Jersey? :) I think maybe someone slipped me some rum. icon_wink.gif


    ditto with what dtlokee said regarding subnet zero.

    We have cowboys here.
    Oldest on-going rodeo in the nation is based in cowtown, NJ in salem county.

    I don't consider myself from NJ. I am from the state of Southern NJ
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  • NetstudentNetstudent Member Posts: 1,693 ■■■□□□□□□□
    nah I'm still here in my office studying while listening to testout. Leaving at 2, getting some lunch, and headin over.
    There is no place like 127.0.0.1 BUT 209.62.5.3 is my 127.0.0.1 away from 127.0.0.1!
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