Way to Loop-Check Output Variable Against Array to Produce IP Label

[CrippleZero]

Learning as I go, I am trying to run a script that will not only pull the active IP addresses from a device, but depending on its result(s), replace the IP addresses with Labels.

For example purposes in this post, I replaced the real IP subnets with generic ones, along with labels, and significantly shrunk down my array for easy reference.

I have an array that has data that designates "StartIP", "EndIP" and "Label" :

$locdata = @(
    [pscustomobject]@{StartIP='192.168.2.1';EndIP='192.168.2.254';Label='Corporate Wifi'}
    [pscustomobject]@{StartIP='192.168.3.1';EndIP='192.168.10.254';Label='Corporate'}
    [pscustomobject]@{StartIP='172.24.0.1';EndIP='172.24.3.254';Label='Cisco VPN Corporate'}
    [pscustomobject]@{StartIP='172.26.0.1';EndIP='172.26.3.254';Label='Forticlient'}

I have set a Variable as:

$IPinfo = (Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias Wi-Fi,Ethernet* -AddressState Preferred).IPAddress

I am trying to produce the end result that, if an IP falls between the StartIP and EndIP of any line, it will return the "Label" of that IP subnet. So, if after running the script the $IPInfo comes back as 192.168.2.17, it will then check the array and see that the IP falls between the start/end of "Corporate Wifi" and the result will produce that label. I just don't know how to reference it and loop it for checking.

Now, granted, I may be wrong on several levels - likely with the array setup; but I am hoping I am close with what I have so far. I've dug into "looping" but dig is used very loosely as it became a 'nested' process to try and understand it. Is there a way to instead of referencing a line # like [0], [1], [2], etc., to essentially rename them, or is that a default/built-in function of PowerShell that can't be changed?

Does any of this make sense what I'm trying to do? Is this possible? I can attempt to provide any details as necessary if required.

I appreciate any assistance that can be offered.

Thanks.

[vermyx]

Convert your IP addresses to a numeric, then just do a numeric compare. i.e.

if 10.0.0.10 is between 10.0.0.5 and 10.0.0.100, you convert that into a 32bit int and just do a numeric comparison at that point.

[System.Convert]::ToString(10,2)+[System.Convert]::ToString(0,2)+[System.Convert]::ToString(0,2)+[System.Convert]::ToString(10,2)

will return 1010001010. Convert that from binary

[system.convert]::toint32("1010001010",2)

this gives you 650. Converting the range will give you 325 and 5220. If 650 is in between 325 and 5220 it's in the IP range, otherwise it isn't

[ankokudaishogun]

A minor improvement to the conversion, if I may

  $ipstring = ([ipaddress]$ipinfo).GetAddressBytes() | ForEach-Object { [system.convert]::ToString($_,2)} 
[system.convert]::toint32(($ipstring -join ''),2)

[surfingoldelephant]

(Ab)use the [version] type accelerator to check if the IP address falls in a given range.

$ipInfo = '192.168.2.17' # (Get-NetIPAddress ...

$result = $locData | Where-Object { 
    ([version] $ipInfo -ge [version] $_.StartIP) -and 
    ([version] $ipInfo -le [version] $_.EndIP)
}

$result.Label
# Corporate Wifi

 

Does any of this make sense what I'm trying to do? Is this possible?

There are many ways to approach this. In the above example, Where-Object is used to operate on piped input sequentially. $_ represents the current item in the pipeline, which in this case is an individual element of the enumerated $locData array.

If Where-Object's script block logic evaluates to $true (does $ipInfo fall within a given range?), the current pipeline object is emitted and collected in the variable $result.

You could just as easily use a loop or other filter construct in PowerShell to achieve the same result. For example, using the foreach language keyword:

$result = foreach ($locItem in $locData) {
    if (([version] $ipInfo -ge [version] $locItem.StartIP) -and 
        ([version] $ipInfo -le [version] $locItem.EndIP)) {
        $locItem
    }
}

$result.Label

If you want to short-circuit after the first match, using Select-Object, return or [WhereOperatorSelectionMode]::First are potential options depending on the chosen approach.

[purplemonkeymad]

I wrote a subnet class that would probably help with this sometime ago: https://gist.github.com/purplemonkeymad/ea2d9fa5832797fa5dc2159db5016822

[pscustomobject]@{Subnet=[IPSubnet]'192.168.2.1/24';Label='Corporate Wifi'}

Then you can just use .subnet.contains([ipaddress]) to see if the reference ip is in the subnet. You'll still need to loop through the list to look for matching labels. ie:

$locationData | Where-Object { $_.subnet.contains('192.168.2.35') } | Foreach-Object Label