Subnetting question

Blang008Blang008 Posts: 61Member ■■□□□□□□□□
What is the first valid host on the subnetwork that the node 192.168.145.246/28 belongs to?


I know how to find the subnet mask, increment, and network ranges. My question is: Is there a quick way to find what network range 192.168.145.246 belongs to?

Comments

  • miller811miller811 Posts: 897Member
    Blang008 wrote: »
    What is the first valid host on the subnetwork that the node 192.168.145.246/28 belongs to?


    I know how to find the subnet mask, increment, and network ranges. My question is: Is there a quick way to find what network range 192.168.145.246 belongs to?

    Determine the block size based on the subnet mask and then count forward, or backward in the this case to determine the subnet, add one to determine the first available host.
    I don't claim to be an expert, but I sure would like to become one someday.

    Quest for 11K pages read in 2011
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  • typeshtypesh Posts: 168Member
    Since you already know the increment is 16, and the subnet mask is 255.255.255.240, then you know that 192.168.1.240 is the last subnet. The .246 host happens to fall in this subnet. This will only apply to situations like these where the host falls into the last block size and is somewhat obvious (based on the subnet mask and increment size). Almost like using the increment size to count backwards. Had the host been something like 192.168.1.132, then the quickest way I could think of is just to count (forwards or backwards) in increments of 16 until you hit 192.168.1.128 (which is the subnet that .132 resides when using /28.).
  • miller811miller811 Posts: 897Member
    here is a good link to practice subnetting.
    IP Subnet Practice
    I don't claim to be an expert, but I sure would like to become one someday.

    Quest for 11K pages read in 2011
    Page Count total to date - 1283
  • NeekoNeeko Posts: 170Member
    Blang008 wrote: »
    What is the first valid host on the subnetwork that the node 192.168.145.246/28 belongs to?


    I know how to find the subnet mask, increment, and network ranges. My question is: Is there a quick way to find what network range 192.168.145.246 belongs to?

    In this case 256 - 16.

    Or 10 x 16 = 160, 5 x 16 = 80. Add the two to get 240.

    Basic maths and common sense is the key.
  • citinerdcitinerd Posts: 266Member
    Neeko wrote: »
    10 x 16 = 160, 5 x 16 = 80. Add the two to get 240.

    Ok I am good at subnetting and all. I am interested in where you get the numbers. I pretty much just have it memorized, but this looks like an easy way if my brain was to fail me. LOL
  • billscott92787billscott92787 Posts: 933Member
    The numbers come from the subnet block sized. /28 is 255.255.255.240

    Subnet block = 256 - 240 = 16

    You can then determine the increments. The multiplication example is the quickest I have seen so far. If that doesn't work for you, you would have to break them down in blocks starting from:

    0
    16
    32
    48
    64
    80
    96
    112
    128
    144
    160
    176
    208
    224
    240

    From that you can then determine

    192.168.145.240 is the network address 192.168.145.241 is the first host - 192.168.145.254 range 192.168.145.255 is the broadcast
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