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Wired Networks Thread, VLAN subnet size in Technical; Is there any guidance available or best-practice advice for choosing subnet sizes when implementing VLANs? For example - I'm splitting ...
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    VLAN subnet size

    Is there any guidance available or best-practice advice for choosing subnet sizes when implementing VLANs?

    For example - I'm splitting my network into several VLANs, but is there any good reason not to use a /16 mask (as it's easier for the rest of my team to understand) on the VLANs even if there's only going to be say, worst case scenario 300 devices on one VLAN rather than going for a /23 mask?

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    23 bit is a good size for 300 devices.
    Whys is 16bit easier to understand? It's way too large 65,000 addresses makes it more complicated in my eyes

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    I usually size my VLANs for the number of devices I expect to have on them. I dislike wasting IP address space.

    Online IP Subnet Calculator

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    It's more from a subnet mask point of view.... 255.255.0.0 is what they're currently used to, rather than 255.255.254.0 which I think will confuse them.

    Maybe it's time for me to do some lessons!

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    Quote Originally Posted by Geoff View Post
    I usually size my VLANs for the number of devices I expect to have on them. I dislike wasting IP address space.

    Online IP Subnet Calculator
    As this bloke said, you don't want to waste addresses. Look at VLSM (Variable Length Subnet Masking).

    If you designate say 1.0.0.0/24 for a subnet that has only 64 hosts you are wasting 192 available IP addresses.

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    Size the VLAN appropriate to how many devices you currently have and then add "x" amount for future growth. One of the ideas behind a vlan is to break broadcast domains thus improving efficency therefore the larger it is the more broadcasts on that vlan defeating one of the purposes of a vlan

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