255.255.255.0 versus 255.255.252.0 - TCP-IP

This is a discussion on 255.255.255.0 versus 255.255.252.0 - TCP-IP ; Gurus, Say run a small internal network on the 172.16.x.x range. Typically, you would run with a 255.255.255.0 subnet masks to get you 254 hosts on this subnet. Now, say I mask at 255.255.252.0. Does this now mean I can ...

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Thread: 255.255.255.0 versus 255.255.252.0

  1. 255.255.255.0 versus 255.255.252.0

    Gurus,

    Say run a small internal network on the 172.16.x.x range. Typically, you
    would run with a 255.255.255.0 subnet masks to get you 254 hosts on this
    subnet. Now, say I mask at 255.255.252.0. Does this now mean I can get 512
    hosts on the subnet?

    --
    Spin


  2. Re: 255.255.255.0 versus 255.255.252.0

    Spin wrote:
    > Gurus,
    >
    > Say run a small internal network on the 172.16.x.x range. Typically,
    > you would run with a 255.255.255.0 subnet masks to get you 254 hosts on
    > this subnet. Now, say I mask at 255.255.252.0. Does this now mean I
    > can get 512 hosts on the subnet?
    >


    It means you get 1022 hosts on each subnet.

    Here's a way to work it out for yourself:

    Equation from Binary:
    2^ remaining host bits 2 = Hosts per Subnet

    Example: There are still 14 host bits remaining; 2^14 - 2 = 16382



    Equation from CIDR:
    2^ (32-CIDR) - 2 = Hosts per Subnet

    Example: There are 14 host bits remaining: 2^ (32-18) - 2 = 16382 subnets


  3. Re: 255.255.255.0 versus 255.255.252.0

    On Aug 29, 11:56*am, "Spin" wrote:
    > Gurus,
    >
    > Say run a small internal network on the 172.16.x.x range. *Typically, you
    > would run with a 255.255.255.0 subnet masks to get you 254 hosts on this
    > subnet. *Now, say I mask at 255.255.252.0. *Does this now mean I can get 512
    > hosts on the subnet?
    >
    > --
    > Spin


    http://www.cisco.com/en/US/tech/tk36...80093f33.shtml

  4. Re: 255.255.255.0 versus 255.255.252.0

    Intuitive wrote:
    > Spin wrote:
    >> Gurus,
    >>
    >> Say run a small internal network on the 172.16.x.x range. Typically,
    >> you would run with a 255.255.255.0 subnet masks to get you 254 hosts
    >> on this subnet. Now, say I mask at 255.255.252.0. Does this now mean
    >> I can get 512 hosts on the subnet?
    >>

    >
    > It means you get 1022 hosts on each subnet.
    >
    > Here's a way to work it out for yourself:
    >
    > Equation from Binary:
    > 2^ remaining host bits 2 = Hosts per Subnet
    >
    > Example: There are still 14 host bits remaining; 2^14 - 2 = 16382


    A mask of 255.255.252.0 yields 10 host bits, not 14.

    2^10 - 2 = 1022 hosts, as you've stated.

    >
    >
    >
    > Equation from CIDR:
    > 2^ (32-CIDR) - 2 = Hosts per Subnet
    >
    > Example: There are 14 host bits remaining: 2^ (32-18) - 2 = 16382 subnets
    >


    Best Regards,
    News Reader

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