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Latest post 10-14-2016 2:01 PM by Martinl. 6 replies.
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  • 09-21-2016 5:13 PM

    IP Subnetting help

    Can this IP address, exist on this subnet Thank you. 

    • Post Points: 80
  • 09-21-2016 8:05 PM In reply to

    Re: IP Subnetting help

    A /22 will give you the following bit pattern in the 3rd octect: 1111 1100. This translates to 128+64+32+16+8+4 which gives 252. So the mask is You then subtract 252 from 256. This gives you the subnet id increment of 4 (the cisco book call this the magic number).

    100 can be divided by 4 without remainder so you know is a valid subnet id given the subnet mask. You know the increment is 4.

    Can you complete?




    • Post Points: 5
  • 09-21-2016 8:11 PM In reply to

    Re: IP Subnetting help


    Can this IP address, exist on this subnet Thank you. 

    Hello, will not belong to

    EDIT: My original wording was bad. Sorry for the confusing way of describing things originally. There are 1024 addresses in The last address in that subnet will be the broadcast address Since the value in your 3rd octet is 104 and that's bigger than the 3rd octect for the last address in this network, you know that it can not belong to

    • Post Points: 20
  • 09-22-2016 11:34 AM In reply to

    • DennisD
    • Top 25 Contributor
    • Joined on 02-26-2010
    • Northern Virginia
    • Elite
    • Points 10,065

    Re: IP Subnetting help

    The network is

    First Host Address is

    Number of Hosts: 1022 (2 to the 10th - 2) = 1022

    Last Possible Host is

    Broadcast Address  is


    Answer still is that would not fall within that network


    • Post Points: 5
  • 09-27-2016 4:48 AM In reply to

    Re: IP Subnetting help

    Thank you.

    • Post Points: 5
  • 10-10-2016 8:00 AM In reply to

    Re: IP Subnetting help

    You can think of a /22 as 4x /24ā€™sā€” hence that prefix would cover the following range: -

    I have found to be useful for testing my subnetting theory with practical challenges, give it a shot :)

    - Michael

    On 22 September 2016 at 10:17:28 AM, ak47inusa ( wrote:

    Can this IP address, exist on this subnet Thank you. 

    INE - The Industry Leader in CCIE Preparation

    • Post Points: 5
  • 10-14-2016 2:01 PM In reply to

    Re: IP Subnetting help

    Lots of vidoes on u-tube that do show subnetting (learn how to) and practice site for subnetting (with question and answers)

    • Post Points: 5
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