Validering af IP adr

'**************************************
' Name: Function to test for a valid IP
'    Address
' Description:This function will return
'    True if the passed value is a valid IP A
'    ddress. I basically made this for my DNS
'    Hostname DLL I was working on so that I
'    could use just one method. Works REALLY
'    fast.
' By: _maniac_
'
' Inputs:Host As String
'
' Returns:True if the Host is a valid IP
'    Address, False if not.
'


Public Function IsIPAddress(Host As String) As Boolean
   
    'Quick length test
    If Len(Host) > 15 Or Len(Host) < 7 Then
        'Host is longer or shorter than possible IP
        IsIPAddress = False
        Exit Function
    End If
   
    'Split components between periods
    Dim tmpParts() As String
    Dim i As Integer
    tmpParts = Split(Host, ".")
   
    'Check number of components
    If UBound(tmpParts) <> 3 Then
        'Not correct numbers of periods/components
        IsIPAddress = False
        Exit Function
    Else
        'Follows IP format - Check each component
        For i = 1 To UBound(tmpParts)
            If IsNumeric(tmpParts(i)) = False Or Len(tmpParts(i)) > 3 Then
                'Non-numeric or too long
                IsIPAddress = False
                Exit Function
            Else
                'Test value
                If CInt(tmpParts(i)) > 255 Then
                    'Value too large
                    IsIPAddress = False
                    Exit Function
                End If
            End If
        Next
    End If
   
    'Passed all tests
    IsIPAddress = True
End Function

Fandt denne