C#中用UdpClient怎么抓不同IP的包？

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class l_Server
    {
        static byte[] buffer = new byte[8192];
        static AsyncCallback _callback_onReceive = new AsyncCallback(callback_onReceive);

        static void Main(string[] args)
        {
            UdpState state = new UdpState();
            state.client.BeginReceive(_callback_onReceive, state);

            while (true)
            {
                string str = Console.ReadLine();
                byte[] b = Encoding.UTF8.GetBytes(str);
            }
        }

        static void callback_onReceive(IAsyncResult result)
        {
            UdpState state = (UdpState)(result.AsyncState);

            buffer = state.client.EndReceive(result, ref state.endpoint);
            Console.WriteLine("Client[" + state.endpoint.Address + "]: " + Encoding.UTF8.GetString(buffer));

            byte[] str = Encoding.UTF8.GetBytes("Received.");
            state.client.Connect(state.endpoint);
            state.client.SendAsync(str, str.Length);

            state.client.BeginReceive(_callback_onReceive, state);
        }
    }

    class UdpState
    {
        public UdpClient client;
        public IPEndPoint endpoint;

        public UdpState()
        {
            this.endpoint = new IPEndPoint(IPAddress.Any, 54464);
            this.client = new UdpClient(endpoint);
        }
    }
}

以上就是我的代码，在实际运行的时候无法接收到第二个IP发来的包( ´_ゝ`)

感觉是Connect导致的，但是没有找到Disconnect方法