Testing IP addresses in powershell.ps1

# The "i'm up late and shouldn't be writing code" method. 
# License: Public Domain - use however you desire, no strings attached. 
# Strings attached: There are none, but you can attribute me in your source code comment if you want to

function Test-PrivateIP {
    param(
    $IPAddress
    )
    $PrivateSubnetAddressList = 
    (([ipaddress]"10.0.0.0").address -band ([ipaddress]"255.0.0.0").address),
    (([ipaddress]"172.16.0.0").address -band ([ipaddress]"255.240.0.0").address),
    (([ipaddress]"192.168.0.0").address -band ([ipaddress]"255.255.0.0").address),
    (([ipaddress]"169.254.0.0").address -band ([ipaddress]"255.255.0.0").address)
    
    
    if ((([ipaddress]$IPAddress).Address -band ([ipaddress]"255.0.0.0").address) -in $PrivateSubnetAddressList) {
        return $IPAddress
    }
    if ((([ipaddress]$IPAddress).Address -band ([ipaddress]"255.240.0.0").address) -in $PrivateSubnetAddressList) {
        return $IPAddress
    }
    if ((([ipaddress]$IPAddress).Address -band ([ipaddress]"255.255.0.0").address) -in $PrivateSubnetAddressList) {
        return $IPAddress
    }
}



$IPAddressList = 
"10.121.23.2",
"204.23.23.2",
"192.168.6.1",
"192.167.254.3",
"10.0.254.201"

foreach ($IPAddress in $IPAddressList) {
    Test-PrivateIP $IPAddress
}