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'System & API - How to Get Machine IP Address

Option Explicit
 
Public Const MAX_WSADescription = 256
Public Const MAX_WSASYSStatus = 128
Public Const ERROR_SUCCESS As Long = 0
Public Const WS_VERSION_REQD As Long = &H101
Public Const WS_VERSION_MAJOR As Long = WS_VERSION_REQD \ &H100 And &HFF&
Public Const WS_VERSION_MINOR As Long = WS_VERSION_REQD And &HFF&
Public Const MIN_SOCKETS_REQD As Long = 1
Public Const SOCKET_ERROR As Long = -1
Public Type HOSTENT
    hName As Long
    hAliases As Long
    hAddrType As Integer
    hLen As Integer
    hAddrList As Long
End Type
Public Type WSADATA
    wVersion As Integer
    wHighVersion As Integer
    szDescription(0 To MAX_WSADescription) As Byte
    szSystemStatus(0 To MAX_WSASYSStatus) As Byte
    wMaxSockets As Integer
    wMaxUDPDG As Integer
    dwVendorInfo As Long
End Type
Public Declare Function WSAGetLastError Lib "WSOCK32.DLL" () As Long
Public Declare Function WSAStartup Lib "WSOCK32.DLL" (ByVal wVersionRequired As Long, _
    lpWSADATA As WSADATA) As Long
Public Declare Function WSACleanup Lib "WSOCK32.DLL" () As Long
Public Declare Function gethostname Lib "WSOCK32.DLL" (ByVal szHost As String, _
    ByVal dwHostLen As Long) As Long
Public Declare Function gethostbyname Lib "WSOCK32.DLL" (ByVal szHost As String) As Long
Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, _
    ByVal hpvSource As Long, ByVal cbCopy As Long)
 
Public Function GetIPAddress() As String
    Dim sHostName As String * 256
    Dim HOST As HOSTENT
    Dim lpHost As Long, dwIPAddr As Long
    Dim tmpIPAddr() As Byte
    Dim I As Integer
    Dim sIPAddr As String
    If Not SocketsInitialize() Then
        GetIPAddress = ""
        Exit Function
    End If
    If gethostname(sHostName, 256) = SOCKET_ERROR Then
        GetIPAddress = ""
        MsgBox "Windows Sockets error " & Str$(WSAGetLastError()) & " has occurred. Unable to successfully get Host Name."
        SocketsCleanup
        Exit Function
    End If
    sHostName = Trim$(sHostName)
    lpHost = gethostbyname(sHostName)
    If lpHost = 0 Then
        GetIPAddress = ""
        MsgBox "Windows Sockets are not responding. " & "Unable to successfully get Host Name."
        SocketsCleanup
        Exit Function
    End If
    CopyMemory HOST, lpHost, Len(HOST)
    CopyMemory dwIPAddr, HOST.hAddrList, 4
    ReDim tmpIPAddr(1 To HOST.hLen)
    CopyMemory tmpIPAddr(1), dwIPAddr, HOST.hLen
    For I = 1 To HOST.hLen
        sIPAddr = sIPAddr & tmpIPAddr(I) & "."
    Next
    GetIPAddress = Mid$(sIPAddr, 1, Len(sIPAddr) - 1)
    SocketsCleanup
End Function
 
Public Function GetIPHostName() As String
    Dim sHostName As String * 256
    If Not SocketsInitialize() Then
        GetIPHostName = ""
        Exit Function
    End If
    If gethostname(sHostName, 256) = SOCKET_ERROR Then
        GetIPHostName = ""
        MsgBox "Windows Sockets error " & Str$(WSAGetLastError()) & " has occurred. Unable to successfully get Host Name."
        SocketsCleanup
        Exit Function
    End If
    GetIPHostName = Left$(sHostName, InStr(sHostName,  chr ( 0 ) ) - 1)
    SocketsCleanup
End Function
 
Public Function HiByte(ByVal wParam As Integer)
    HiByte = wParam \ &H100 And &HFF&
End Function
 
Public Function LoByte(ByVal wParam As Integer)
    LoByte = wParam And &HFF&
End Function
 
Public Sub SocketsCleanup()
    If WSACleanup() <> ERROR_SUCCESS Then
        MsgBox "Socket error occurred in Cleanup."
    End If
End Sub
 
Public Function SocketsInitialize() As Boolean
    Dim WSAD As WSADATA
    Dim sLoByte As String
    Dim sHiByte As String
    If WSAStartup(WS_VERSION_REQD, WSAD) <> ERROR_SUCCESS Then
        MsgBox "The 32-bit Windows Socket is not responding."
        SocketsInitialize = False
        Exit Function
    End If
    If WSAD.wMaxSockets < MIN_SOCKETS_REQD Then
        MsgBox "This application requires a minimum of " & CStr(MIN_SOCKETS_REQD) & " supported sockets."
        SocketsInitialize = False
        Exit Function
    End If
    If LoByte(WSAD.wVersion) < WS_VERSION_MAJOR Or (LoByte(WSAD.wVersion) = WS_VERSION_MAJOR And HiByte(WSAD.wVersion) < WS_VERSION_MINOR) Then
        sHiByte = CStr(HiByte(WSAD.wVersion))
        sLoByte = CStr(LoByte(WSAD.wVersion))
        MsgBox "Sockets version " & sLoByte & "." & sHiByte & " is not supported by 32-bit Windows Sockets."
        SocketsInitialize = False
        Exit Function
    End If
    SocketsInitialize = True
End Function
 
Private Sub Form_Load()
    MsgBox "IP Host Name: " & GetIPHostName()
    MsgBox "IP Address: " & GetIPAddress()
End Sub