How To Call GetNetworkParams/GetAdaptersInfo From Visual Basic (223025)


The information in this article applies to:

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
  • Microsoft Visual Basic Learning Edition for Windows 6.0
  • Microsoft Visual Basic Learning Edition for Windows 5.0
  • Microsoft Visual Basic Professional Edition for Windows 6.0
  • Microsoft Visual Basic Professional Edition for Windows 5.0
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
  • Microsoft Visual Basic Enterprise Edition for Windows 5.0
  • Microsoft Visual Basic Control Creation Edition for Windows 5.0
  • Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
  • Microsoft Windows 98
  • Microsoft Windows Millennium Edition
This article was previously published under Q223025

SUMMARY

This article illustrates how to programmatically retrieve IP configuration information similar to the IPCONFIG.EXE utility. It demonstrates how to use the IP Helper APIs GetNetworkParams() and GetAdaptersInfo() from Visual Basic.

The libraries called by the code sample in this article are only supported on the following platforms:

Microsoft Windows 2000
Microsoft Windows 98
Microsoft Windows Millennium Edition (Me)

Running it on any other platform results in an error.

MORE INFORMATION

  1. Start a new Visual Basic Standard EXE project. Form1 is created by default.
  2. On the Project menu, click Remove Form1.
  3. On the Project menu, click Add Module. Module1 is created by default.
  4. Paste the following code in the General Declarations section of Module1:
    Public Const MAX_HOSTNAME_LEN = 132
Public Const MAX_DOMAIN_NAME_LEN = 132
Public Const MAX_SCOPE_ID_LEN = 260
Public Const MAX_ADAPTER_NAME_LENGTH = 260
Public Const MAX_ADAPTER_ADDRESS_LENGTH = 8
Public Const MAX_ADAPTER_DESCRIPTION_LENGTH = 132
Public Const ERROR_BUFFER_OVERFLOW = 111
Public Const MIB_IF_TYPE_ETHERNET = 6
Public Const MIB_IF_TYPE_TOKENRING = 9
Public Const MIB_IF_TYPE_FDDI = 15
Public Const MIB_IF_TYPE_PPP = 23
Public Const MIB_IF_TYPE_LOOPBACK = 24
Public Const MIB_IF_TYPE_SLIP = 28

Type IP_ADDR_STRING
            Next As Long
            IpAddress As String * 16
            IpMask As String * 16
            Context As Long
End Type

Type IP_ADAPTER_INFO
            Next As Long
            ComboIndex As Long
            AdapterName As String * MAX_ADAPTER_NAME_LENGTH
            Description As String * MAX_ADAPTER_DESCRIPTION_LENGTH
            AddressLength As Long
            Address(MAX_ADAPTER_ADDRESS_LENGTH - 1) As Byte
            Index As Long
            Type As Long
            DhcpEnabled As Long
            CurrentIpAddress As Long
            IpAddressList As IP_ADDR_STRING
            GatewayList As IP_ADDR_STRING
            DhcpServer As IP_ADDR_STRING
            HaveWins As Byte
            PrimaryWinsServer As IP_ADDR_STRING
            SecondaryWinsServer As IP_ADDR_STRING
            LeaseObtained As Long
            LeaseExpires As Long
End Type

Type FIXED_INFO
            HostName As String * MAX_HOSTNAME_LEN
            DomainName As String * MAX_DOMAIN_NAME_LEN
            CurrentDnsServer As Long
            DnsServerList As IP_ADDR_STRING
            NodeType As Long
            ScopeId  As String * MAX_SCOPE_ID_LEN
            EnableRouting As Long
            EnableProxy As Long
            EnableDns As Long
End Type

Public Declare Function GetNetworkParams Lib "IPHlpApi.dll" _
       (FixedInfo As Any, pOutBufLen As Long) As Long
Public Declare Function GetAdaptersInfo Lib "IPHlpApi.dll" _
       (IpAdapterInfo As Any, pOutBufLen As Long) As Long
Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
       (Destination As Any, Source As Any, ByVal Length As Long)

Sub main()
    Dim error As Long
    Dim FixedInfoSize As Long
    Dim AdapterInfoSize As Long
    Dim i As Integer
    Dim PhysicalAddress  As String
    Dim NewTime As Date
    Dim AdapterInfo As IP_ADAPTER_INFO
    Dim AddrStr As IP_ADDR_STRING
    Dim FixedInfo As FIXED_INFO
    Dim Buffer As IP_ADDR_STRING
    Dim pAddrStr As Long
    Dim pAdapt As Long
    Dim Buffer2 As IP_ADAPTER_INFO
    Dim FixedInfoBuffer() As Byte
    Dim AdapterInfoBuffer() As Byte
    
    ' Get the main IP configuration information for this machine
    ' using a FIXED_INFO structure.
    FixedInfoSize = 0
    error = GetNetworkParams(ByVal 0&, FixedInfoSize)
    If error <> 0 Then
        If error <> ERROR_BUFFER_OVERFLOW Then
           MsgBox "GetNetworkParams sizing failed with error " & error
           Exit Sub
        End If
    End If
    ReDim FixedInfoBuffer(FixedInfoSize - 1)
    
    error = GetNetworkParams(FixedInfoBuffer(0), FixedInfoSize)
    If error = 0 Then
            CopyMemory FixedInfo, FixedInfoBuffer(0), FixedInfoSize
            MsgBox "Host Name:  " & FixedInfo.HostName
            MsgBox "DNS Servers:  " & FixedInfo.DnsServerList.IpAddress
            pAddrStr = FixedInfo.DnsServerList.Next
            Do While pAddrStr <> 0
                  CopyMemory Buffer, ByVal pAddrStr, LenB(Buffer)
                  MsgBox "DNS Servers:  " & Buffer.IpAddress
                  pAddrStr = Buffer.Next
            Loop
            
            Select Case FixedInfo.NodeType
                       Case 1
                                  MsgBox "Node type: Broadcast"
                       Case 2
                                  MsgBox "Node type: Peer to peer"
                       Case 4
                                  MsgBox "Node type: Mixed"
                       Case 8
                                  MsgBox "Node type: Hybrid"
                       Case Else
                                  MsgBox "Unknown node type"
            End Select
            
            MsgBox "NetBIOS Scope ID:  " & FixedInfo.ScopeId
            If FixedInfo.EnableRouting Then
                       MsgBox "IP Routing Enabled "
            Else
                       MsgBox "IP Routing not enabled"
            End If
            If FixedInfo.EnableProxy Then
                       MsgBox "WINS Proxy Enabled "
            Else
                       MsgBox "WINS Proxy not Enabled "
            End If
            If FixedInfo.EnableDns Then
                      MsgBox "NetBIOS Resolution Uses DNS "
            Else
                      MsgBox "NetBIOS Resolution Does not use DNS  "
            End If
    Else
            MsgBox "GetNetworkParams failed with error " & error
            Exit Sub
    End If
    
    ' Enumerate all of the adapter specific information using the
    ' IP_ADAPTER_INFO structure.
    ' Note:  IP_ADAPTER_INFO contains a linked list of adapter entries.
    
    AdapterInfoSize = 0
    error = GetAdaptersInfo(ByVal 0&, AdapterInfoSize)
    If error <> 0 Then
        If error <> ERROR_BUFFER_OVERFLOW Then
           MsgBox "GetAdaptersInfo sizing failed with error " & error
           Exit Sub
        End If
    End If
    ReDim AdapterInfoBuffer(AdapterInfoSize - 1)

    ' Get actual adapter information
    error = GetAdaptersInfo(AdapterInfoBuffer(0), AdapterInfoSize)
    If error <> 0 Then
       MsgBox "GetAdaptersInfo failed with error " & error
       Exit Sub
    End If
   
    ' Allocate memory
     CopyMemory AdapterInfo, AdapterInfoBuffer(0), AdapterInfoSize
    pAdapt = AdapterInfo.Next

    Do
     CopyMemory Buffer2, AdapterInfo, AdapterInfoSize
       Select Case Buffer2.Type
              Case MIB_IF_TYPE_ETHERNET
                   MsgBox "Adapter name: Ethernet adapter "
              Case MIB_IF_TYPE_TOKENRING
                   MsgBox "Adapter name: Token Ring adapter "
              Case MIB_IF_TYPE_FDDI
                   MsgBox "Adapter name: FDDI adapter "
              Case MIB_IF_TYPE_PPP
                   MsgBox "Adapter name: PPP adapter"
              Case MIB_IF_TYPE_LOOPBACK
                   MsgBox "Adapter name: Loopback adapter "
              Case MIB_IF_TYPE_SLIP
                   MsgBox "Adapter name: Slip adapter "
              Case Else
                   MsgBox "Adapter name: Other adapter "
       End Select
       MsgBox "AdapterDescription: " & Buffer2.Description

       PhysicalAddress = ""
       For i = 0 To Buffer2.AddressLength - 1
           PhysicalAddress = PhysicalAddress & Hex(Buffer2.Address(i))
           If i < Buffer2.AddressLength - 1 Then
              PhysicalAddress = PhysicalAddress & "-"
           End If
       Next
       MsgBox "Physical Address: " & PhysicalAddress
    
       If Buffer2.DhcpEnabled Then
          MsgBox "DHCP Enabled "
       Else
          MsgBox "DHCP disabled"
       End If

       MsgBox "IP Address: " & Buffer2.IpAddressList.IpAddress
       MsgBox "Subnet Mask: " & Buffer2.IpAddressList.IpMask
       pAddrStr = Buffer2.IpAddressList.Next
       Do While pAddrStr <> 0
          CopyMemory Buffer, Buffer2.IpAddressList, LenB(Buffer)
          MsgBox "IP Address: " & Buffer.IpAddress
          MsgBox "Subnet Mask: " & Buffer.IpMask
          pAddrStr = Buffer.Next
          If pAddrStr <> 0 Then
             CopyMemory Buffer2.IpAddressList, ByVal pAddrStr, _
                        LenB(Buffer2.IpAddressList)
          End If
       Loop
    
       MsgBox "Default Gateway: " & Buffer2.GatewayList.IpAddress
       pAddrStr = Buffer2.GatewayList.Next
       Do While pAddrStr <> 0
          CopyMemory Buffer, Buffer2.GatewayList, LenB(Buffer)
          MsgBox "IP Address: " & Buffer.IpAddress
          pAddrStr = Buffer.Next
          If pAddrStr <> 0 Then
             CopyMemory Buffer2.GatewayList, ByVal pAddrStr, _
                        LenB(Buffer2.GatewayList)
          End If
       Loop

       MsgBox "DHCP Server: " & Buffer2.DhcpServer.IpAddress
       MsgBox "Primary WINS Server: " & _
              Buffer2.PrimaryWinsServer.IpAddress
       MsgBox "Secondary WINS Server: " & _
              Buffer2.SecondaryWinsServer.IpAddress

       ' Display time.
       NewTime = DateAdd("s", Buffer2.LeaseObtained, #1/1/1970#)
       MsgBox "Lease Obtained: " & _
              CStr(Format(NewTime, "dddd, mmm d hh:mm:ss yyyy"))
     
       NewTime = DateAdd("s", Buffer2.LeaseExpires, #1/1/1970#)
       MsgBox "Lease Expires :  " & _
              CStr(Format(NewTime, "dddd, mmm d hh:mm:ss yyyy"))
       pAdapt = Buffer2.Next
       If pAdapt <> 0 Then
           CopyMemory AdapterInfo, ByVal pAdapt, AdapterInfoSize
        End If
      Loop Until pAdapt = 0
End Sub
  5. Press the F5 key to run the project, click OK on each of the message boxes that are displayed, and note the results.
Running this sample as compiled, EXE gives the following error message at the end:
Runtime error 10: this array is fixed and temporary locked.
Running this inside IDE generates IPF at VB6.EXE at the end.

REFERENCES

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

Q193059 INFO: IP Helper APIs Add Net Config and Stat Info to Win32 Apps

Q234573 BUG:IPHelper API Do Not Work Correctly After Install IE 5.0 on Windows 98

Modification Type:MinorLast Reviewed:12/21/2004
Keywords:kbAPI kbhowto kbIPHelp KB223025
©2004 Microsoft Corporation. All rights reserved.