Hi, I found this program that would get the mac address of a computer given its IP. I converted it into vb.net and it gave 2 errors. It said that I couldn't use "any" in declarations, so I found out what variable it was tryign to pass and changed the any to that data type. Now, the program will start in vb.net... but when I click the button, it returns the wrong mac address, while the one in vb6 returned the correct one.
All you have to do is add 2 textboxes to the form and 1 button, dont change their names.
::::::::::VB6 CODE::::::::::

Option Explicit

Private Const NO_ERROR = 0

Private Declare Function inet_addr Lib "wsock32.dll" _
  (ByVal s As String) As Long

Private Declare Function SendARP Lib "iphlpapi.dll" _
  (ByVal DestIP As Long, ByVal SrcIP As Long, pMacAddr As Long, PhyAddrLen As Long) As Long

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dst As Any, src As Any, ByVal bcount As Long)
   


Private Sub Form_Load()

   Text1.Text = "192.168.1.101"
   Text2.Text = ""
   Command1.Caption = "Get Remote Mac Address"
   
End Sub


Private Sub Command1_Click()

   Dim sRemoteMacAddress As String
   
   If Len(Text1.Text) > 0 Then
   
      If GetRemoteMACAddress(Text1.Text, sRemoteMacAddress) Then
         Text2.Text = sRemoteMacAddress
      Else
         Text2.Text = "(SendARP call failed)"
      End If
     
   End If

End Sub


Private Function GetRemoteMACAddress(ByVal sRemoteIP As String, _
                                     sRemoteMacAddress As String) As Boolean

   Dim dwRemoteIP As Long
   Dim pMacAddr As Long
   Dim bpMacAddr() As Byte
   Dim PhyAddrLen As Long
   Dim cnt As Long
   Dim tmp As String
   
  'convert the string IP into
  'an unsigned long value containing
  'a suitable binary representation
  'of the Internet address given
   dwRemoteIP = inet_addr(sRemoteIP)
   
   If dwRemoteIP <> 0 Then
   
     'set PhyAddrLen to 6
      PhyAddrLen = 6
   
     'retrieve the remote MAC address
      If SendARP(dwRemoteIP, 0&, pMacAddr, PhyAddrLen) = NO_ERROR Then
     
         If pMacAddr <> 0 And PhyAddrLen <> 0 Then
     
           'returned value is a long pointer
           'to the mac address, so copy data
           'to a byte array
            ReDim bpMacAddr(0 To PhyAddrLen - 1)
            CopyMemory bpMacAddr(0), pMacAddr, ByVal PhyAddrLen
         
           'loop through array to build string
            For cnt = 0 To PhyAddrLen - 1
               
               If bpMacAddr(cnt) = 0 Then
                  tmp = tmp & "00-"
               Else
                  tmp = tmp & Hex$(bpMacAddr(cnt)) & "-"
               End If
         
            Next
           
           'remove the trailing dash
           'added above and return True
            If Len(tmp) > 0 Then
               sRemoteMacAddress = Left$(tmp, Len(tmp) - 1)
               GetRemoteMACAddress = True
            End If

            Exit Function
         
         Else
            GetRemoteMACAddress = False
         End If
           
      Else
         GetRemoteMACAddress = False
      End If  'SendARP
     
   Else
      GetRemoteMACAddress = False
   End If  'dwRemoteIP
     
End Function


::::::::::VB.NET Code::::::::::

Option Strict Off
Option Explicit On
Imports VB = Microsoft.VisualBasic
Friend Class Form1
    Inherits System.Windows.Forms.Form
#Region "Windows Form Designer generated code "
    Public Sub New()
        MyBase.New()
        If m_vb6FormDefInstance Is Nothing Then
            If m_InitializingDefInstance Then
                m_vb6FormDefInstance = Me
            Else
                Try 
                    'For the start-up form, the first instance created is the default instance.
                    If System.Reflection.Assembly.GetExecutingAssembly.EntryPoint.DeclaringType Is Me.GetType Then
                        m_vb6FormDefInstance = Me
                    End If
                Catch
                End Try
            End If
        End If
        'This call is required by the Windows Form Designer.
        InitializeComponent()
    End Sub
    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal Disposing As Boolean)
        If Disposing Then
            If Not components Is Nothing Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(Disposing)
    End Sub
    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer
    Public ToolTip1 As System.Windows.Forms.ToolTip
    Public WithEvents Command1 As System.Windows.Forms.Button
    Public WithEvents Text2 As System.Windows.Forms.TextBox
    Public WithEvents Text1 As System.Windows.Forms.TextBox
    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(Form1))
        Me.components = New System.ComponentModel.Container()
        Me.ToolTip1 = New System.Windows.Forms.ToolTip(components)
        Me.ToolTip1.Active = True
        Me.Command1 = New System.Windows.Forms.Button
        Me.Text2 = New System.Windows.Forms.TextBox
        Me.Text1 = New System.Windows.Forms.TextBox
        Me.Text = "Form1"
        Me.ClientSize = New System.Drawing.Size(312, 206)
        Me.Location = New System.Drawing.Point(4, 30)
        Me.StartPosition = System.Windows.Forms.FormStartPosition.WindowsDefaultLocation
        Me.Font = New System.Drawing.Font("Arial", 8!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.BackColor = System.Drawing.SystemColors.Control
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable
        Me.ControlBox = True
        Me.Enabled = True
        Me.KeyPreview = False
        Me.MaximizeBox = True
        Me.MinimizeBox = True
        Me.Cursor = System.Windows.Forms.Cursors.Default
        Me.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.ShowInTaskbar = True
        Me.HelpButton = False
        Me.WindowState = System.Windows.Forms.FormWindowState.Normal
        Me.Name = "Form1"
        Me.Command1.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
        Me.Command1.Text = "Command1"
        Me.Command1.Size = New System.Drawing.Size(129, 57)
        Me.Command1.Location = New System.Drawing.Point(144, 128)
        Me.Command1.TabIndex = 2
        Me.Command1.Font = New System.Drawing.Font("Arial", 8!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Command1.BackColor = System.Drawing.SystemColors.Control
        Me.Command1.CausesValidation = True
        Me.Command1.Enabled = True
        Me.Command1.ForeColor = System.Drawing.SystemColors.ControlText
        Me.Command1.Cursor = System.Windows.Forms.Cursors.Default
        Me.Command1.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.Command1.TabStop = True
        Me.Command1.Name = "Command1"
        Me.Text2.AutoSize = False
        Me.Text2.Size = New System.Drawing.Size(225, 49)
        Me.Text2.Location = New System.Drawing.Point(40, 56)
        Me.Text2.TabIndex = 1
        Me.Text2.Text = "Text2"
        Me.Text2.Font = New System.Drawing.Font("Arial", 8!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Text2.AcceptsReturn = True
        Me.Text2.TextAlign = System.Windows.Forms.HorizontalAlignment.Left
        Me.Text2.BackColor = System.Drawing.SystemColors.Window
        Me.Text2.CausesValidation = True
        Me.Text2.Enabled = True
        Me.Text2.ForeColor = System.Drawing.SystemColors.WindowText
        Me.Text2.HideSelection = True
        Me.Text2.ReadOnly = False
        Me.Text2.Maxlength = 0
        Me.Text2.Cursor = System.Windows.Forms.Cursors.IBeam
        Me.Text2.MultiLine = False
        Me.Text2.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.Text2.ScrollBars = System.Windows.Forms.ScrollBars.None
        Me.Text2.TabStop = True
        Me.Text2.Visible = True
        Me.Text2.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.Text2.Name = "Text2"
        Me.Text1.AutoSize = False
        Me.Text1.Size = New System.Drawing.Size(225, 41)
        Me.Text1.Location = New System.Drawing.Point(40, 8)
        Me.Text1.TabIndex = 0
        Me.Text1.Text = "Text1"
        Me.Text1.Font = New System.Drawing.Font("Arial", 8!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Text1.AcceptsReturn = True
        Me.Text1.TextAlign = System.Windows.Forms.HorizontalAlignment.Left
        Me.Text1.BackColor = System.Drawing.SystemColors.Window
        Me.Text1.CausesValidation = True
        Me.Text1.Enabled = True
        Me.Text1.ForeColor = System.Drawing.SystemColors.WindowText
        Me.Text1.HideSelection = True
        Me.Text1.ReadOnly = False
        Me.Text1.Maxlength = 0
        Me.Text1.Cursor = System.Windows.Forms.Cursors.IBeam
        Me.Text1.MultiLine = False
        Me.Text1.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.Text1.ScrollBars = System.Windows.Forms.ScrollBars.None
        Me.Text1.TabStop = True
        Me.Text1.Visible = True
        Me.Text1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.Text1.Name = "Text1"
        Me.Controls.Add(Command1)
        Me.Controls.Add(Text2)
        Me.Controls.Add(Text1)
    End Sub
#End Region 
#Region "Upgrade Support "
    Private Shared m_vb6FormDefInstance As Form1
    Private Shared m_InitializingDefInstance As Boolean
    Public Shared Property DefInstance() As Form1
        Get
            If m_vb6FormDefInstance Is Nothing OrElse m_vb6FormDefInstance.IsDisposed Then
                m_InitializingDefInstance = True
                m_vb6FormDefInstance = New Form1()
                m_InitializingDefInstance = False
            End If
            DefInstance = m_vb6FormDefInstance
        End Get
        Set
            m_vb6FormDefInstance = Value
        End Set
    End Property
#End Region 
    
    Private Const NO_ERROR As Short = 0
    
    Private Declare Function inet_addr Lib "wsock32.dll" (ByVal s As String) As Integer
    
    Private Declare Function SendARP Lib "iphlpapi.dll" (ByVal DestIP As Integer, ByVal SrcIP As Integer, ByRef pMacAddr As Integer, ByRef PhyAddrLen As Integer) As Integer
    
    Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (ByRef dst As Byte, ByRef src As Integer, ByVal bcount As Integer)
    
    
    
    Private Sub Form1_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load
        
        Text1.Text = "192.168.0.103"
        Text2.Text = ""
        Command1.Text = "Get Remote Mac Address"
        
    End Sub
    
    
    Private Sub Command1_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command1.Click
        
        Dim sRemoteMacAddress As String
        
        If Len(Text1.Text) > 0 Then
            
            If GetRemoteMACAddress(Text1.Text, sRemoteMacAddress) Then
                Text2.Text = sRemoteMacAddress
            Else
                Text2.Text = "(SendARP call failed)"
            End If
            
        End If
        
    End Sub
    
    
    Private Function GetRemoteMACAddress(ByVal sRemoteIP As String, ByRef sRemoteMacAddress As String) As Boolean
        
        Dim dwRemoteIP As Integer
        Dim pMacAddr As Integer
        Dim bpMacAddr() As Byte
        Dim PhyAddrLen As Integer
        Dim cnt As Integer
        Dim tmp As String
        
        'convert the string IP into
        'an unsigned long value containing
        'a suitable binary representation
        'of the Internet address given
        dwRemoteIP = inet_addr(sRemoteIP)
        
        If dwRemoteIP <> 0 Then
            
            'set PhyAddrLen to 6
            PhyAddrLen = 6
            
            'retrieve the remote MAC address
            If SendARP(dwRemoteIP, 0, pMacAddr, PhyAddrLen) = NO_ERROR Then
                
                If pMacAddr <> 0 And PhyAddrLen <> 0 Then
                    
                    'returned value is a long pointer
                    'to the mac address, so copy data
                    'to a byte array
                    ReDim bpMacAddr(PhyAddrLen - 1)
                    CopyMemory(bpMacAddr(0), pMacAddr, PhyAddrLen)
                    
                    'loop through array to build string
                    For cnt = 0 To PhyAddrLen - 1
                        
                        If bpMacAddr(cnt) = 0 Then
                            tmp = tmp & "00-"
                        Else
                            tmp = tmp & Hex(bpMacAddr(cnt)) & "-"
                        End If
                        
                    Next 
                    
                    'remove the trailing dash
                    'added above and return True
                    If Len(tmp) > 0 Then
                        sRemoteMacAddress = VB.Left(tmp, Len(tmp) - 1)
                        GetRemoteMACAddress = True
                    End If
                    
                    Exit Function
                    
                Else
                    GetRemoteMACAddress = False
                End If
                
            Else
                GetRemoteMACAddress = False
            End If 'SendARP
            
        Else
            GetRemoteMACAddress = False
        End If 'dwRemoteIP
        
    End Function
End Class


When I copied the above code, I copeid everything, so if you want to test it, you have to delete all code from the form, including the code that the compiler puts in for you. Sorry, I did not notice this when I copied it.

What MAC address are you trying to retrieve?  And what version of the .NET Framework?  Might check:
http://www.15seconds.com/issue/051215.htm
Jeff
Please:  Don't forget to click "Mark as Answer" on the post that helped you.  That way future readers will know which post solved your issue.

Hi, I am trying to get the computers MAC address. This would be the adapter's address. I need this inorder to use Wake On Lan so I can start up remote computers on the network.

The question is whether you wated to get the local system MAC or a remote MAC.  You may need permissions for the remote MAC.  Did you look at the link?
Jeff
Please:  Don't forget to click "Mark as Answer" on the post that helped you.  That way future readers will know which post solved your issue.

Yes, I need the remote MAC and I am network administrator. I have looked at the link, and System.Net.NyetworkInformation.PhysicalAddress seems to be what I need. This only takes in byte information, so I would have to convert the IP into byte first. Thank you.

did you already find the problem? you have only integer datatypes but there should be some long. the mac address is 48 bit but integer is only 32. So when ever you want a variable to contain a macaddress it should be long.
Thomas