再给大家一个国外的类。超级好的东西。呵呵。

/******************************************************************************************************************
*    Class:                Trace
*    Description:        Traces path of an ip packet with its respond time
*    Author:                Sanjay Ahuja
*    Date:                5/15/2002
*    Copyright?            ?2002, Sanjay Ahuja (lparam@hotmail.com). Use it as you want till you leave my name intact
/******************************************************************************************************************/


using System;
using System.Net;
using System.Net.Sockets;


//ICMP constants
struct ICMPConstants
{
    public const int ICMP_ECHOREPLY= 0;            // Echo reply query
    public const int ICMP_TIMEEXCEEDED= 11;        // TTL exceeded error
    public const int ICMP_ECHOREQ=    8;            // Echo request query
    public const int MAX_TTL= 256;                // Max TTL
}

//ICMP header, size is 8 bytes
struct ICMP
{
    public byte    type;                // Type
    public byte    code;                // Code
    public ushort    checksum;        // Checksum
    public ushort    id;                // Identification
    public ushort    seq;            // Sequence
}

// ICMP Echo Request, size is 12+ 32 (PACKET_SIZE as defined in class Trace)= 44 bytes
struct REQUEST
{
    public ICMP    m_icmp;
    public byte    []m_data;
}

class Trace
{
    const int PACKET_SIZE= 32;

    public static void Main(string[] args)
    {
        try
        {
            //verify command line
            if(args.Length== 0)
            {
                Console.WriteLine("usage: trace <hostname>");
                return;
            }

            //Create Raw ICMP Socket
            Socket s= new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Icmp);
            //destination
            IPEndPoint ipdest= new IPEndPoint(Dns.Resolve(args[0]).AddressList[0],80);
            //Source
            IPEndPoint ipsrc= new IPEndPoint(Dns.GetHostByName(Dns.GetHostName()).AddressList[0],80);
            EndPoint epsrc= (EndPoint)ipsrc;
                
            ICMP ip= new ICMP();
            ip.type = ICMPConstants.ICMP_ECHOREQ;
            ip.code = 0;
            ip.checksum = 0;
            ip.id = (ushort)DateTime.Now.Millisecond;    //any number you feel is kinda unique :)
            ip.seq  = 0;
            
            REQUEST req= new REQUEST();
            req.m_icmp= ip;
            req.m_data = new Byte[PACKET_SIZE];
                
            //Initialize data
            for (int i = 0; i < req.m_data.Length; i++)
            {
                req.m_data[i] = (byte)''S'';
            }

            //this function would gets byte array from the REQUEST structure
            Byte[] ByteSend= CreatePacket(req);

            //send requests with increasing number of TTL
            for(int ittl=1; ittl<= ICMPConstants.MAX_TTL; ittl++)
            {
                Byte[] ByteRecv = new Byte[256];
                //Socket options to set TTL and Timeouts
                s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.IpTimeToLive, ittl);
                s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout,10000);
                s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout,10000);

                //Get current time
                DateTime dt= DateTime.Now;
                //Send Request
                int iRet= s.SendTo(ByteSend, ByteSend.Length, SocketFlags.None, ipdest);
                //check for Win32 SOCKET_ERROR
                if(iRet== -1)
                    Console.WriteLine("error sending data");

                //Receive
                iRet= s.ReceiveFrom(ByteRecv, ByteRecv.Length, SocketFlags.None, ref epsrc);

                //Calculate time required
                TimeSpan ts= DateTime.Now- dt;;

                //check if response is OK
                if(iRet== -1)
                    Console.WriteLine("error getting data");

                Console.WriteLine("TTL= {0,-5} IP= {1,-20} Time= {2,3}ms",ittl,((IPEndPoint)epsrc).Address,ts.Milliseconds);
                //reply size should be sizeof REQUEST + 20 (i.e sizeof IP header),it should be an echo reply
                //and id should be same
                if((iRet == PACKET_SIZE+ 8 +20)&& (BitConverter.ToInt16(ByteRecv,24) == BitConverter.ToInt16(ByteSend,4))&& (ByteRecv[20] == ICMPConstants.ICMP_ECHOREPLY))
                    break;
                //time out
                if(ByteRecv[20] != ICMPConstants.ICMP_TIMEEXCEEDED)
                {
                    Console.WriteLine("unexpected reply, quitting...");
                    break;
                }
            }
        }
        catch(SocketException e)
        {
            Console.WriteLine(e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine(e.Message);
        }

    }

    
    public static byte[] CreatePacket( REQUEST req )
    {
        Byte[] ByteSend= new Byte[PACKET_SIZE+ 8];
        //Create Byte array from REQUEST structure
        ByteSend[0]= req.m_icmp.type;
        ByteSend[1]= req.m_icmp.code;
        Array.Copy(BitConverter.GetBytes(req.m_icmp.checksum), 0, ByteSend, 2, 2);
        Array.Copy(BitConverter.GetBytes(req.m_icmp.id), 0, ByteSend, 4, 2);
        Array.Copy(BitConverter.GetBytes(req.m_icmp.seq), 0, ByteSend, 6, 2);
        for(int i=0; i< req.m_data.Length; i++)
            ByteSend[i+8]= req.m_data[i];

        //calculate checksum
        int iCheckSum = 0;
        for (int i= 0; i < ByteSend.Length; i+= 2)
            iCheckSum += Convert.ToInt32( BitConverter.ToUInt16(ByteSend,i));

        iCheckSum = (iCheckSum >> 16) + (iCheckSum & 0xffff);
        iCheckSum += (iCheckSum >> 16);

        //update byte array to reflect checksum
        Array.Copy(BitConverter.GetBytes((ushort)~iCheckSum), 0, ByteSend, 2, 2);
        return ByteSend;
    }

}