#I used hash tables in this way as I feel it is more intuative for configuration than a multi-array.
$Org_List = @{"192.168.0.0/28" = "ou=site1,dc=test,dc=local";
              "192.168.3.0/24" = "ou=site2,dc=test,dc=local";
              "172.16.0.0/24" = "ou=site2,dc=test,dc=local"}


#Configure
$Computer_List = get-adcomputer -filter { Enabled -eq $true } -searchbase "CN=computers,DC=test,dc=local" | select DnsHostName, DistinguishedName

#OutPut the max Range for the provide ip and CIDR 192.168.0.0/24 is the expected format
function find-ipcidr() {
    Param(  [Parameter(Mandatory = $true)]$IP_Cidr )

$Ip_Cidr = $IP_Cidr.Split("/")
$Ip_Bin = ($IP_Cidr[0] -split '\.' | ForEach-Object {[System.Convert]::ToString($_,2).PadLeft(8,'0')}).ToCharArray()
    for($i=0;$i -lt $Ip_Bin.length;$i++){
        if($i -ge $Ip_Cidr[1]){
        $Ip_Bin[$i] = "1"
        }
    }

[string[]]$IP_Int = @()
    for($i = 0;$i -lt $Ip_Bin.length;$i++) {
    $PartIpBin += $Ip_Bin[$i]
        if(($i+1)%8 -eq 0){
        $PartIpBin = $PartIpBin -join ""
        $IP_Int += [Convert]::ToInt32($PartIpBin -join "",2)
        $PartIpBin = ""
        }
    }

$IP_Int = $IP_Int -join "."
return $IP_Int
}

#convert the provided IP into an 32 bit integer in order to easier work with in it.
function ip_to_int32(){
    Param(  [Parameter(Mandatory = $true)]$IP_int32 )
$IP_int32_arr = $IP_int32.split(".")
$return_int32 = ([Convert]::ToInt32($IP_int32_arr[0])*16777216 +[Convert]::ToInt32($IP_int32_arr[1])*65536 +[Convert]::ToInt32($IP_int32_arr[2])*256 +[Convert]::ToInt32($IP_int32_arr[3]))
return $return_int32
}

#Go through the list of computers gathered at the top of the script, get the ip address via DNS.
#Find the max range for each value in the hash table and if the ip falls into that range move the computer object to corresponding OU.
foreach($computer in $computer_list) {
$Comp_Dns = $computer.DnsHostName
    try {
    $Comp_IP = [System.Net.Dns]::GetHostAddresses("$Comp_Dns") | where-object { $_.AddressFamily -eq 'InterNetwork'} | select -expandproperty IPAddressToString
    } catch {
    echo "Error On lookup of $Comp_Dns :  $_"
    $Comp_IP = $FALSE
    }

    if($Comp_IP) {
        foreach($ip_info in $Org_List.GetEnumerator().Name) {
        $start_of_range_arr = $ip_info.Split("/")
        [string] $start_of_range_value = $start_of_range_arr[0]
        $start_of_range_int32 = ip_to_int32 $start_of_range_value

        $end_of_range_value = find-ipcidr $ip_info
        $end_of_range_int32 = ip_to_int32 $end_of_range_value

        $search_ip_int32 = ip_to_int32 $Comp_IP

        echo "Start: $start_of_range_value End: $end_of_range_value Looking for: $comp_ip"
            if(($search_ip_int32 -ge $start_of_range_int32) -and ($search_ip_int32 -le $end_of_range_int32)) {
            echo "Found $comp_ip"
            $DistinguishedName = $computer.DistinguishedName
            try {
            Move-ADObject -identity "$DistinguishedName" -TargetPath $Org_List."$ip_info"
            } catch {
            echo "Error On moving $Comp_Dns :  $_"
            }
            }
        }
    }
}