Question

我写了一个UDP端口扫描程序。我将数据包发送到同一网络中的另一台设备，但这里有一点问题，如果我在不同的端口发送10个数据包（每个端口关闭），wireshark只接收一个数据包。我应该收到10个ICMP包，其类型为：3。我应该在代码中更改哪些内容才能获得这些内容？

using PcapDotNet.Core;
using PcapDotNet.Packets;
using PcapDotNet.Packets.Ethernet;
using PcapDotNet.Packets.IpV4;
using PcapDotNet.Packets.Transport;
using System;
using System.Collections.Generic;

namespace SendingASinglePacketWithSendPacket
{
class Program
{
    static void Main(string[] args)
    {
        IList<LivePacketDevice> allDevices = LivePacketDevice.AllLocalMachine;
        PacketDevice selectedDevice = allDevices[2];


        for (int i = 1; i < 10; i++)
        {
            new Sender().SendUDPandGetStatus(selectedDevice, (ushort)i);
        }


        System.Console.ReadKey();
    }
}

class Sender
{
    public void SendUDPandGetStatus(PacketDevice selectedDevice, ushort port)
    {
        using (PacketCommunicator communicator = selectedDevice.Open(100, PacketDeviceOpenAttributes.Promiscuous, -1))
        {           
            communicator.SendPacket(BuildUdpPacket(port));
        }
    }

    private static Packet BuildUdpPacket(ushort destinationPort)
    {
        EthernetLayer ethernetLayer = new EthernetLayer
        { 
            Destination = new MacAddress("14:cc:20:2c:7e:36"),
            Source = new MacAddress("9C:4E:36:17:86:48"),

            EtherType = EthernetType.None,
        };

        IpV4Layer ipV4Layer =new IpV4Layer
        {
            Source = new IpV4Address("192.168.0.104"),
            CurrentDestination = new IpV4Address("192.168.0.105"),
            Fragmentation = IpV4Fragmentation.None,
            HeaderChecksum = null, 
            Identification = 123,
            Options = IpV4Options.None,
            Ttl = 30,
            TypeOfService = 0,
        };

        UdpLayer udpLayer = new UdpLayer
        {
            SourcePort = 4050,
            DestinationPort = destinationPort,
            Checksum = null, 
            CalculateChecksumValue = true,
        };

        PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, udpLayer);
        return builder.Build(DateTime.Now);
    }
}
}

Wireshark结果：

如果我把断点放在行上，我只会添加：

new Sender().SendUDPandGetStatus(selectedDevice, (ushort)i);

并按下F5按钮（5s间隔），得到正确的结果。

Answer 1

这是我在Nmap文档中找到的内容：

Nmap检测速率限制并相应减慢以避免用目标机器将无用的数据包淹没网络下降。不幸的是，每秒一个数据包的Linux风格限制进行65,536端口扫描需要超过18个小时。超速的想法你的UDP扫描包括并行扫描更多的主机，做一个首先快速扫描流行的端口，从后面扫描防火墙，并使用--host-timeout跳过慢速主机。

Documentation

端口扫描器 - icmp数据包

1 个答案: