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1543 Views 7 Replies Latest reply: Dec 18, 2010 3:45 AM by Zaher Hamiyah RSS

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question about subneting

Dec 30, 2010 4:50 PM

student 143 posts since
Aug 4, 2010

Hello Guys,


I have some questions about subneting, I have attached the file in this discussion which has the question.


I hope my question is clear.



Message was edited to remove exam details by:


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  • cjinfantino 231 posts since
    Sep 13, 2008
    Currently Being Moderated
    1. Dec 17, 2010 5:04 AM (in response to student)
    Re: question about subneting



    Looking at the diagram, the network address under 'Admin' was blurred out. So assuming that is then yes "C" would be a good answer for Network A.


    For Link A I would choose answer "D" and the reason is what they are really asking is to assign addresses to Link A and Network A that will not overlap with other networks (because each router interface is a network boundary). It is also assumed they would want to have the most efficient use of the address space.


    Answer "D" will use the address 0-3 that is currently not being used. Also because it is a link, you will only need two addresses for each interface on the router. A /30 network does just that, 0 will be the network address, .3 is the broadcast address, .1 and .2 will be the addresses for your router interfaces.


    Hope that helps!

  • Currently Being Moderated
    3. Dec 17, 2010 12:47 PM (in response to student)
    Re: question about subneting

    If  the Admin VLAN is /27, then using E for Link A would overlap with this subnet. In order to prevent any overlapping subnets, D is the best answer for Link A.




  • Martin 13,077 posts since
    Jan 16, 2009
    Currently Being Moderated
    4. Dec 17, 2010 2:38 PM (in response to student)
    Re: question about subneting

    C and D are 2 answers. For 120 hosts, you need 7 bits; that leaves 1 bit for subnet, which is /25.

  • Andreas Thrasivoulou 20 posts since
    Jun 26, 2008
    Currently Being Moderated
    6. Dec 18, 2010 3:03 AM (in response to student)
    Re: question about subneting

    For Link A the correct answer is D because is a point to point which you only need 2 IPs usable the /30 link. you dont use E because that IPs can be used in a larger subnet. to better understand break the network in smaller pieces starting from the end.


    You have break these network into to /25 networks and (these will be used for Network A so is gone)


    then break the into smaller and these i believe will help you understand the subnetting

  • Zaher Hamiyah 167 posts since
    Aug 14, 2008
    Currently Being Moderated
    7. Dec 18, 2010 3:45 AM (in response to student)
    Re: question about subneting



    you are posting illegal materials which is totally prohibited.


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