How To Get Network Adapter Address from Visual Basic

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Article ID: 175472 - View products that this article applies to.
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IPX and NETBIOS interfaces require network addresses. This article presents a step-by-step example on how to use Netbios API call to get the network adapter addresses from Microsoft Visual Basic.


Step-by-Step Example

  1. Create a new Standard EXE from Visual Basic. Form1 is created by default.
  2. Add a CommandButton to Form1. Its default name is Command1.
  3. Add the following code to the General Declarations section of Form1:
       Option Explicit
       Private Const NCBASTAT = &H33
       Private Const NCBNAMSZ = 16
       Private Const HEAP_ZERO_MEMORY = &H8
       Private Const HEAP_GENERATE_EXCEPTIONS = &H4
       Private Const NCBRESET = &H32
       Private Type NCB
            ncb_command As Byte 'Integer
            ncb_retcode As Byte 'Integer
            ncb_lsn As Byte 'Integer
            ncb_num As Byte ' Integer
            ncb_buffer As Long 'String
            ncb_length As Integer
            ncb_callname As String * NCBNAMSZ
            ncb_name As String * NCBNAMSZ
            ncb_rto As Byte 'Integer
            ncb_sto As Byte ' Integer
            ncb_post As Long
            ncb_lana_num As Byte 'Integer
            ncb_cmd_cplt As Byte  'Integer
            ncb_reserve(9) As Byte ' Reserved, must be 0
            ncb_event As Long
       End Type
       Private Type ADAPTER_STATUS
            adapter_address(5) As Byte 'As String * 6
            rev_major As Byte 'Integer
            reserved0 As Byte 'Integer
            adapter_type As Byte 'Integer
            rev_minor As Byte 'Integer
            duration As Integer
            frmr_recv As Integer
            frmr_xmit As Integer
            iframe_recv_err As Integer
            xmit_aborts As Integer
            xmit_success As Long
            recv_success As Long
            iframe_xmit_err As Integer
            recv_buff_unavail As Integer
            t1_timeouts As Integer
            ti_timeouts As Integer
            Reserved1 As Long
            free_ncbs As Integer
            max_cfg_ncbs As Integer
            max_ncbs As Integer
            xmit_buf_unavail As Integer
            max_dgram_size As Integer
            pending_sess As Integer
            max_cfg_sess As Integer
            max_sess As Integer
            max_sess_pkt_size As Integer
            name_count As Integer
       End Type
       Private Type NAME_BUFFER
            name  As String * NCBNAMSZ
            name_num As Integer
            name_flags As Integer
       End Type
       Private Type ASTAT
            adapt As ADAPTER_STATUS
            NameBuff(30) As NAME_BUFFER
       End Type
       Private Declare Function Netbios Lib "netapi32.dll" _
               (pncb As NCB) As Byte
       Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" ( _
               hpvDest As Any, ByVal hpvSource As Long, ByVal cbCopy As Long)
       Private Declare Function GetProcessHeap Lib "kernel32" () As Long
       Private Declare Function HeapAlloc Lib "kernel32" _
               (ByVal hHeap As Long, ByVal dwFlags As Long, _
               ByVal dwBytes As Long) As Long
       Private Declare Function HeapFree Lib "kernel32" (ByVal hHeap As Long, _
               ByVal dwFlags As Long, lpMem As Any) As Long
  4. Add the following code to Command1_Click event procedure:
       Sub Command1_Click()
           Dim myNcb As NCB
           Dim bRet As Byte
           myNcb.ncb_command = NCBRESET
           bRet = Netbios(myNcb)
           myNcb.ncb_command = NCBASTAT
           myNcb.ncb_lana_num = 0
           myNcb.ncb_callname = "*               "
           Dim myASTAT As ASTAT, tempASTAT As ASTAT
           Dim pASTAT As Long
           myNcb.ncb_length = Len(myASTAT)
           Debug.Print Err.LastDllError
           pASTAT = HeapAlloc(GetProcessHeap(), HEAP_GENERATE_EXCEPTIONS _
                    Or HEAP_ZERO_MEMORY, myNcb.ncb_length)
           If pASTAT = 0 Then
              Debug.Print "memory allcoation failed!"
              Exit Sub
           End If
           myNcb.ncb_buffer = pASTAT
           bRet = Netbios(myNcb)
           Debug.Print Err.LastDllError
           CopyMemory myASTAT, myNcb.ncb_buffer, Len(myASTAT)
           MsgBox Hex(myASTAT.adapt.adapter_address(0)) & " " & _
                  Hex(myASTAT.adapt.adapter_address(1)) _
                  & " " & Hex(myASTAT.adapt.adapter_address(2)) & " " _
                  & Hex(myASTAT.adapt.adapter_address(3)) _
                  & " " & Hex(myASTAT.adapt.adapter_address(4)) & " " _
                  & Hex(myASTAT.adapt.adapter_address(5))
           HeapFree GetProcessHeap(), 0, pASTAT
       End Sub
  5. Press the F5 key to run the program.
  6. Click on Command1. Note that the network adapter address is displayed in a message box.


Article ID: 175472 - Last Review: July 13, 2004 - Revision: 3.2
  • Microsoft Visual Basic 4.0 Professional Edition
  • Microsoft Visual Basic 5.0 Professional Edition
  • Microsoft Visual Basic 6.0 Professional Edition
  • Microsoft Visual Basic 4.0 Enterprise Edition
  • Microsoft Visual Basic 5.0 Enterprise Edition
  • Microsoft Visual Basic 6.0 Enterprise Edition
kbhowto kbapi kbnetbios kbnetwork KB175472

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