how to broadcast ARP packet in C#

Question

Hi,

I want to send ARP packet through C#. I dont know how to form ARP packet(format) in C# . Can anybody help on this ? Plus how to send arp packet or broadcast it.

Any sample code is highly appreciated. Thanks in Advance.

Answer 1

Here is a library you might be interested in: http://www.beesync.com/packetx/docs/html/index.html

And a Snippit from the send.cs File.

// Get adapter hardware address and IP address
  Adapter oAdapter = (Adapter)oPktX.Adapter;
  string sHWAddr = oAdapter.HWAddress;
  string sIPAddr = oAdapter.NetIP;
  string sIPMask = oAdapter.NetMask;
  Console.WriteLine("MAC Addr = " + sHWAddr);
  Console.WriteLine("IP  Addr = " + sIPAddr);

  // Send ARP request for this IP address
  string sIPReso = "11.12.13.14";
  char [] aDelimiter = {'.'};
  string[] aIPReso = sIPReso.Split(aDelimiter, 4);
  string[] aIPAddr = sIPAddr.Split(aDelimiter, 4);

  // Build ARP packet
  Object[] oPacket = new Object[] { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
    Convert.ToByte("0x" + sHWAddr.Substring(0,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(2,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(4,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(6,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(8,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(10,2), 16),
    0x08, 0x06, 0x00, 0x01,
    0x08, 0x00, 0x06, 0x04, 0x00, 0x01,
    Convert.ToByte("0x" + sHWAddr.Substring(0,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(2,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(4,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(6,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(8,2), 16),
    Convert.ToByte("0x" + sHWAddr.Substring(10,2), 16),
    Convert.ToByte(aIPAddr[0], 10),
    Convert.ToByte(aIPAddr[1], 10),
    Convert.ToByte(aIPAddr[2], 10),
    Convert.ToByte(aIPAddr[3], 10),
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    Convert.ToByte(aIPReso[0], 10),
    Convert.ToByte(aIPReso[1], 10),
    Convert.ToByte(aIPReso[2], 10),
    Convert.ToByte(aIPReso[3], 10),
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

  // Send 100 ARP requests      
  oAdapter.SendPacket(oPacket, 100);

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Edit:

The best way to do this is by using the WinPCap Libraries now they officially come in C and not C# but you can import the wpcap.ddl if you have installed winpcap, Heres some other resources that you may want view:

http://geekswithblogs.net/dotnetnomad/archive/2008/01/31/119140.aspx

http://bytes.com/topic/c-sharp/answers/278941-how-wrap-winpcap

And here is a GUI sniffer with source:

http://www.codeproject.com/KB/IP/dotnetwinpcap.aspx