ip-cider.js

ip-cider.js

const ipToNumber = (ip) => ip.split('.').reduce((acc, octet) => (acc << 8) + parseInt(octet, 10), 0);

const findConsecutiveIPs = (ips) => {
  ips.sort((a, b) => ipToNumber(a) - ipToNumber(b));

  const result = [];
  let startIP = ips[0];
  let endIP = ips[0];

  for (let i = 1; i < ips.length; i++) {
    const currentIP = ips[i];
    const expectedNextIP = ipToNumber(endIP) + 1;

    if (ipToNumber(currentIP) === expectedNextIP) {
      endIP = currentIP;
    } else {
      result.push(startIP === endIP ? startIP : `${startIP}-${endIP}`);
      startIP = endIP = currentIP;
    }
  }

  result.push(startIP === endIP ? startIP : `${startIP}-${endIP}`);
  return result;
};

const consecutiveIPs = [
  '192.168.1.1',
  '192.168.1.2',
  '192.168.1.3',
  '192.168.1.5',
  '192.168.1.6',
  '192.168.1.8',
];

const summarizedCIDRs = findConsecutiveIPs(consecutiveIPs);
console.log(summarizedCIDRs);