Subnet Mask Conversion
This is a helper function to convert a subnet mask written as an IPv4 address to its equivalent suffix.
function subnetSuffix(mask) {
if (mask) {
return mask
.split(".") // ["255", "255", "255", "0"]
.map(i => (i >>> 0).toString(2)) // ["11111111", "11111111", "11111111", "0"]
.join("") // "1111111111111111111111110"
.replace(/0/g, "") // "111111111111111111111111"
.length // 24
}
return 0;
}
subnetSuffix("255.255.255.0"); // 24