private async void button1_Click(object sender, EventArgs e)
        {
            List<string> allIps = new List<string>() {
            "1.160.61.139",
            "1.181.28.71",
            "1.188.1.115",
            "1.203.152.224",
            "1.225.14.12",
            "1.250.247.189",
            "1.36.245.202",
            "103.218.124.116",
            "103.72.58.70",
            "104.101.60.47",
            "104.110.1.197",
            "104.178.194.189",
            "104.202.156.243",
            "104.230.8.35",
            "104.37.176.2",
            "104.76.40.42",
            "105.106.70.222",
            "106.116.2.199",
            "106.210.39.1",
            "106.5.232.215",
            "107.154.138.153",
            "108.171.103.16",
            "108.20.205.216",
            "109.105.32.171",
            "109.198.242.140",
            "109.21.66.18",
            "110.13.205.121",
            "110.216.16.145",
            "110.229.237.35",
            "111.101.35.110",
            "111.13.44.163",
            "111.216.130.21",
            "111.69.228.253",
            "112.195.129.76",
            "112.245.99.181",
            "112.82.163.251",
            "112.87.205.98",
            "113.190.48.52",
            "114.233.62.86",
            "114.253.63.103",
            "115.196.225.222",
            "115.204.214.243",
            "115.211.98.157",
            "115.227.206.60",
            "115.239.98.154",
            "115.68.234.105",
            "115.92.204.68",
            "116.46.29.32",
            "117.10.229.34",
            "117.10.39.181",
            "117.122.167.94",
            "117.168.38.237",
            "117.217.90.80",
            "117.5.122.221",
            "117.63.20.80",
            "118.8.232.185",
            "119.100.36.101",
            "119.164.96.36",
            "119.23.201.86",
            "120.209.183.61",
            "120.218.134.180",
            "121.124.78.201",
            "121.175.227.224",
            "121.178.28.105",
            "121.232.253.60",
            "121.254.54.50",
            "122.141.189.171",
            "122.231.113.64",
            "122.242.222.140",
            "123.118.127.129",
            "123.118.30.182",
            "123.192.248.210",
            "123.234.159.48",
            "124.165.22.167",
            "124.234.118.142",
            "124.244.72.83",
            "125.182.212.101",
            "125.190.206.215",
            "125.46.18.249",
            "126.145.20.138",
            "126.177.200.251",
            "126.68.213.133",
            "127.1.43.216",
            "127.1.65.64",
            "127.126.134.97",
            "127.132.57.110",
            "127.185.238.221",
            "127.186.228.74",
            "127.19.61.39",
            "127.192.248.174",
            "127.221.203.118",
            "127.222.177.172",
            "127.242.116.137",
            "127.245.169.246",
            "127.27.56.74",
            "127.30.217.66",
            "127.48.128.54",
            "127.50.177.243",
            "127.55.49.166",
            "127.63.123.27",
            "127.74.227.182",
            "127.82.254.69",
            "127.97.105.243",
            "129.121.30.131",
            "129.148.8.143",
            "130.81.139.241",
            "131.252.84.93",
            "134.3.58.51",
            "138.128.100.15",
            "14.129.119.3",
            "14.211.184.251",
            "14.42.155.85",
            "14.67.195.52",
            "14.85.18.35",
            "149.114.156.132",
            "149.126.170.1",
            "149.202.197.20",
            "151.101.22.63",
            "151.224.118.188",
            "151.224.204.195",
            "151.226.229.153",
            "151.228.198.139",
            "151.244.164.133",
            "152.179.107.81",
            "152.249.6.63",
            "158.69.213.38",
            "159.180.38.249",
            "159.253.20.166",
            "167.62.105.53",
            "169.44.9.76",
            "171.33.199.252",
            "171.38.217.254",
            "171.80.38.127",
            "173.233.8.42",
            "173.241.103.145",
            "174.53.84.127",
            "174.75.87.151",
            "174.77.225.175",
            "175.116.59.148",
            "175.125.215.83",
            "175.167.254.89",
            "175.198.13.212",
            "176.14.208.99",
            "177.103.185.216",
            "177.131.209.19",
            "177.80.195.155",
            "178.162.70.69",
            "178.166.12.98",
            "178.90.53.76",
            "179.153.196.7",
            "179.236.9.94",
            "180.108.62.15",
            "180.109.1.193",
            "180.122.204.9",
            "181.226.104.226",
            "181.67.116.42",
            "181.93.60.24",
            "182.121.171.59",
            "182.240.49.6",
            "182.46.138.5",
            "183.134.80.175",
            "183.210.105.192",
            "183.25.251.246",
            "184.186.156.158",
            "184.3.106.220",
            "184.5.96.61",
            "185.58.173.59",
            "186.113.48.191",
            "186.4.228.75",
            "186.45.2.104",
            "187.139.55.150",
            "187.159.16.176",
            "187.193.181.231",
            "187.221.87.95",
            "187.234.216.178",
            "188.168.115.214",
            "188.177.169.181",
            "188.37.179.185",
            "188.61.115.5",
            "188.7.218.15",
            "189.159.10.177",
            "189.168.140.28",
            "189.174.99.173",
            "189.31.211.222",
            "190.182.5.68",
            "190.193.60.105",
            "190.2.180.57",
            "190.232.139.67",
            "190.246.92.27",
            "190.46.31.72",
            "190.47.11.116",
            "190.47.72.84",
            "192.227.103.18",
            "192.99.58.35",
            "193.3.62.6",
            "195.214.164.137",
            "195.88.100.133",
            "198.129.80.4",
            "198.15.131.106",
            "198.44.169.254",
            "199.96.59.118",
            "2.123.153.102",
            "2.125.19.20",
            "2.178.108.11",
            "200.161.230.164",
            "200.237.192.106",
            "201.152.115.218",
            "201.166.215.34",
            "201.178.93.243",
            "201.202.191.1",
            "201.240.212.48",
            "201.54.97.143",
            "201.69.127.136",
            "201.91.213.81",
            "202.110.84.158",
            "202.123.91.44",
            "203.87.8.126",
            "204.10.140.216",
            "205.185.121.86",
            "206.45.32.143",
            "208.106.188.35",
            "209.169.73.243",
            "209.189.202.140",
            "210.157.211.140",
            "211.193.167.27",
            "211.230.187.221",
            "213.14.83.117",
            "217.125.217.6",
            "217.126.64.166",
            "217.145.211.32",
            "217.236.133.156",
            "217.71.92.23",
            "218.150.103.166",
            "218.61.59.87",
            "219.239.51.21",
            "220.134.82.170",
            "220.76.68.202",
            "221.225.178.60",
            "221.9.121.149",
            "221.90.78.51",
            "222.72.76.148",
            "223.81.168.192",
            "223.84.138.4",
            "23.204.244.138",
            "23.212.72.42",
            "23.222.160.211",
            "23.242.88.157",
            "23.36.212.49",
            "24.1.231.233",
            "24.240.165.137",
            "24.250.245.44",
            "24.34.124.100",
            "24.8.142.45",
            "27.155.33.169",
            "27.218.116.200",
            "27.232.97.9",
            "27.238.90.254",
            "31.165.219.238",
            "36.96.115.135",
            "37.15.166.94",
            "37.191.91.58",
            "39.130.138.131",
            "39.177.190.9",
            "39.83.39.1",
            "39.84.112.125",
            "41.248.177.163",
            "41.36.3.48",
            "42.103.244.227",
            "42.113.213.158",
            "42.235.20.37",
            "42.4.133.48",
            "46.12.146.106",
            "46.174.200.227",
            "46.182.115.215",
            "46.203.64.110",
            "46.231.63.110",
            "46.84.19.226",
            "47.148.84.160",
            "47.158.71.209",
            "49.151.179.76",
            "49.67.196.61",
            "49.79.128.201",
            "5.128.139.37",
            "5.164.144.29",
            "5.29.115.18",
            "5.56.140.252",
            "50.159.84.91",
            "50.204.188.177",
            "50.26.130.31",
            "50.49.212.150",
            "52.1.39.245",
            "58.18.68.248",
            "58.243.225.10",
            "59.165.217.87",
            "60.189.181.39",
            "60.19.34.187",
            "60.190.251.95",
            "60.213.209.106",
            "60.97.165.111",
            "61.53.232.119",
            "62.31.169.97",
            "62.43.196.73",
            "64.173.182.24",
            "64.25.117.133",
            "65.51.226.173",
            "66.175.211.219",
            "66.234.203.91",
            "67.127.177.113",
            "67.141.84.38",
            "67.172.200.58",
            "67.182.129.225",
            "67.189.29.54",
            "67.225.136.243",
            "67.249.205.189",
            "67.254.70.122",
            "67.55.237.251",
            "68.49.197.235",
            "70.94.96.241",
            "71.222.101.251",
            "71.3.134.220",
            "71.56.138.174",
            "72.143.112.19",
            "72.193.121.171",
            "72.216.214.70",
            "72.73.110.228",
            "73.126.89.168",
            "73.178.126.222",
            "73.187.229.34",
            "73.229.209.38",
            "73.231.3.10",
            "73.250.108.2",
            "74.110.217.209",
            "74.114.119.205",
            "74.233.252.40",
            "76.168.111.35",
            "77.123.51.108",
            "77.129.29.116",
            "77.152.58.57",
            "77.205.59.165",
            "77.214.56.2",
            "77.85.224.214",
            "77.9.48.6",
            "78.100.56.174",
            "78.125.49.126",
            "78.192.92.201",
            "78.219.212.148",
            "78.71.248.154",
            "79.105.177.104",
            "79.167.188.62",
            "79.20.10.233",
            "79.236.229.1",
            "79.250.19.65",
            "79.35.187.143",
            "80.153.247.152",
            "80.180.84.126",
            "80.212.234.14",
            "80.221.3.169",
            "81.129.218.24",
            "81.17.72.121",
            "81.198.2.50",
            "81.240.25.91",
            "81.62.49.239",
            "81.65.228.164",
            "82.177.126.231",
            "82.199.55.213",
            "82.232.9.144",
            "82.251.9.243",
            "82.56.3.55",
            "82.94.221.112",
            "83.173.192.177",
            "83.50.57.137",
            "83.55.16.40",
            "84.210.209.201",
            "84.99.51.67",
            "85.128.198.239",
            "85.26.37.245",
            "86.121.102.36",
            "86.124.99.150",
            "87.167.43.136",
            "87.172.146.97",
            "87.180.36.223",
            "87.2.81.163",
            "87.222.179.53",
            "87.227.249.202",
            "87.239.104.35",
            "87.248.66.148",
            "88.102.234.219",
            "88.126.198.167",
            "88.165.145.248",
            "88.173.88.57",
            "88.180.108.86",
            "88.180.221.150",
            "89.109.195.47",
            "89.134.166.17",
            "89.163.173.178",
            "89.22.169.186",
            "91.134.100.163",
            "91.37.99.201",
            "91.43.189.156",
            "92.101.152.178"};

            var tasks = allIps.Select(ip =>
                new Ping().SendPingAsync(ip, 400)
          );
            var results = await Task.WhenAll(tasks);
            int i = 0;
            foreach (var r in results) {

                textBox1.AppendText(i+ "    "+ r.Address + "  " +r.Status+"   "+ r.RoundtripTime + Environment.NewLine);
                i++;
            }
            textBox1.AppendText("End!" + Environment.NewLine);




        }