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@bluefangs
Last active December 17, 2018 17:41
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random-ip-from-subnet ==> Produces a crudely random IP address from a given subnet.
function getIPFromSubnet(subnetRange) {
// subnetRange = "10.0.0.0/24"
const subnet = subnetRange.split('/')[0]; // 10.0.0.0
const mask = subnetRange.split('/')[1]; // 24
const ipArray = subnet.split('.'); //["10", "0", "0", "0"]
var ipInBinary = ""; // will contain the binary equivalent of the iP
// for each element in the array, convert from decimal to binary
for (let quad of ipArray) {
let octet = parseInt(quad, 10).toString(2)
// we need each octet to be 8 bits. So provide padding for those which are less than 8 bits
// 0101 becomes 00000101
let octetLength = octet.length
if (octetLength < 8) {
let octDiff = 8 - octetLength;
octet = "0".repeat(octDiff) + octet
}
// concat all the octets into a 32 bit binary
ipInBinary = ipInBinary.concat(octet) // 00001010000000000000000000000000
}
// console.log("ipInBinary: ", ipInBinary);
// strip the subnet from the entire address:
let subnetBinary = ipInBinary.slice(0, mask) // 000010100000000000000000
let hostsBinary = ipInBinary.slice(mask, ipInBinary.length) // 00000000
var randomBinarySubstitute = "";
const randomPool = "10101010101010101010101010101010" //fix this nonsense later.
for(let i=0; i<32-mask; i++){
randomBinarySubstitute += randomPool[Math.floor(Math.random() * ipInBinary.length)]
}
let newIPBinary = subnetBinary + randomBinarySubstitute;
let finalIP = "";
// split the 32 bit binary IP into an array of 8 bits, each representing an octate
let finalIPArray_binary = newIPBinary.match(/.{8}/g) // ["00001010", "00000000", "00000000", "10001010"]
// convert the binary quad array to decimal dotted quad
for (let element of finalIPArray_binary) {
finalIP = finalIP + "." + parseInt(element, 2);
finalIP = finalIP.replace(/^\./, ""); // remnove the leading .
}
console.log("FinalIP" , finalIP)
return finalIP
}
getIPFromSubnet('10.0.0.0/16')
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