Get a machines MAC address on the local network from its IP in C#

Question

I am trying write a function that takes a single IP address as a parameter and queries that machine on my local network for it\'s MAC address.

Answer 1

using System.Net;
using System.Runtime.InteropServices;

[DllImport("iphlpapi.dll", ExactSpelling = true)]
public static extern int SendARP(int DestIP, int SrcIP, [Out] byte[] pMacAddr, ref int PhyAddrLen);

try
{
    IPAddress hostIPAddress = IPAddress.Parse("XXX.XXX.XXX.XX");
    byte[] ab = new byte[6];
    int len = ab.Length, 
        r = SendARP((int)hostIPAddress.Address, 0, ab, ref len);
    Console.WriteLine(BitConverter.ToString(ab, 0, 6));
}
catch (Exception ex) { }

or with PC Name

try
      {
           Tempaddr = System.Net.Dns.GetHostEntry("DESKTOP-xxxxxx");
      }
      catch (Exception ex) { }
      byte[] ab = new byte[6];
      int len = ab.Length, r = SendARP((int)Tempaddr.AddressList[1].Address, 0, ab, ref len);
        Console.WriteLine(BitConverter.ToString(ab, 0, 6));