ldc-web/app/Http/Controllers/API/NetworksController.php

<?php

namespace App\Http\Controllers\API;

use App\Http\Controllers\Controller;
use App\Models\Network;

class NetworksController extends Controller
{
    /**
     * Api Networks
     *
     * @return \Illuminate\Http\Response|\Illuminate\Contracts\Routing\ResponseFactory
     */
    public function index()
    {
        $ips = [];

        $networks = Network::all();
        foreach ($networks as $network) {
            $infos = explode('.', $network->first_ip);
            $min = $infos[3];
            $max = explode('.', $network->last_ip)[3];
            for ($i = $min; $i <= $max; $i++) {
                $ips[] = "$infos[0].$infos[1].$infos[2].$i";
            }
        }
        return response($ips);
    }
}