Binaryworld - LanCardAddress - Read the Ethernet address of a LAN card ... [ VB -> Networking ]

Const NCBNAMSZ = 16

Private Type NCB
  ncb_command As Byte
  ncb_retcode As Byte
  ncb_lsn As Byte
  ncb_num As Byte
  ncb_buffer As Long
  ncb_length As Integer
  ncb_callname As String * NCBNAMSZ
  ncb_name As String * NCBNAMSZ
  ncb_rto As Byte
  ncb_sto As Byte
  ncb_post As Long
  ncb_lana_num As Byte
  ncb_cmd_cplt As Byte
  ncb_reserve(9) As Byte
  ncb_event As Long
End Type

Private Type ADAPTER_STATUS
  adapter_address(5) As Byte
  rev_major As Byte
  reserved0 As Byte
  adapter_type As Byte
  rev_minor As Byte
  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(10) As NAME_BUFFER
End Type

Private Declare Function Netbios Lib "netapi32.dll" (pncb As NCB) As Byte

' Read the Ethernet address of a LAN card.
' This number can be considered to uniquely identify a network adapter

Private Function LanCardAddress(ByVal cardNum As Long) As String
  Dim ncbInfo As NCB
  Dim astatInfo As ASTAT
  Dim i As Integer

  Const NCBASTAT = &H33
  Const NCBRESET = &H32

  'Reset the card
  ncbInfo.ncb_command = NCBRESET
  Netbios ncbInfo

  ' Get info from the card
  ncbInfo.ncb_command = NCBASTAT
  ncbInfo.ncb_lana_num = cardNum
  ncbInfo.ncb_callname = "* "
  ncbInfo.ncb_length = Len(astatInfo)
  ' prepare the address where the result is to be delivered
  ncbInfo.ncb_buffer = VarPtr(astatInfo)
  Netbios ncbInfo

  ' read the result
  For i = 0 To 5
    LanCardAddress = LanCardAddress & Right$("00" & Hex$ _
      (astatInfo.adapt.adapter_address(i)), 2)
  Next

End Function