So I have a script that is ANDing an IPv4 address and a subnet address. Not checking to see if it is a valid input (which I should add), it converts the input to binary.
if ($readInput -match "y"){
$readIP = read-host "Please input an IPv4 address to be ANDed "
# need to add subnet mask later.
$readSub = read-host "Please input the Subnet Mask "
#need to delimite '.'
#$readIP.split "."
#$readSub.split "."
#need to join them
#convert IPv4 address to binary, period seperated at each octet. (input ip, base 2)
$binIP = [convert]::ToString($readIP,2)
write-host "$binIP" -backgroundcolor "white" -foregroundcolor "black"
## need to have two 32 element array that compares each 1 and 0. loop through each one with a counter and compare them with
## conditional if statements
#conditional statements for /cider notion to equal a binary number (mask, base 2)
$binSub = [convert]::ToString($readSub,2)
write-host "$binSub" -backgroundcolor "white" -foregroundcolor "black"
}
The input is:
19216823
2552552550
The output is:
1001001010011100110110111
10011000001001001101110001100110
Do I have to add 7 trailing 0's at the end of the IP address in order to perform proper ANDing?
It's usually easier to use the [IPAddress] class. Example:
$ip = [IPAddress] "192.168.32.76"
$networkMask = [IPAddress] "255.255.255.0"
$networkID = [IPAddress] ($ip.Address -band $networkMask.Address)
$networkID.IPAddressToString # outputs "192.168.32.0"
If you want to count the bits in a network mask string, you can use a function like this:
function ConvertTo-IPv4MaskBits {
param(
[parameter(Mandatory=$true)]
[String] $MaskString
)
$mask = ([IPAddress] $MaskString).Address
for ( $bitCount = 0; $mask -ne 0; $bitCount++ ) {
$mask = $mask -band ($mask - 1)
}
$bitCount
}
This function assumes a correctly formed network mask ID.
A full write-up and some more functions are available in an article I wrote a while back: