Input Mask/Validation for IP Address

What would be the proper input mask and validation rule for an IP Address?  I don't want to force all three digits.

For example you could say an IP address is always three digits but I want it to accept that, or

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I would not use an input mask. Rather, validate the input with something like:

Function IsIP(pvarAdr) As Boolean

    Dim varNumbers As Variant
    Dim bytI As Byte

    If IsNull(pvarAdr) Then Exit Function
    varNumbers = Split(pvarAdr, ".")
    If UBound(varNumbers) <> 3 Then Exit Function
    For bytI = 0 To 3
        If Not IsNumeric(varNumbers(bytI)) Then Exit Function
        If InStr(varNumbers(bytI), " ") Then Exit Function
        If Val(varNumbers(bytI)) < 0 Then Exit Function
        If Val(varNumbers(bytI)) > 255 Then Exit Function
    Next bytI
    IsIP = True

End Function

To make thinks complete, you can use the KeyPress event to allow only digits, dots and backspace. This way, nothing can go wrong :)


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Ah, well, here is the KeyPress event handler:

Private Sub txtIPAddress_KeyPress(KeyAscii As Integer)

    Select Case KeyAscii
        Case vbKey0 To vbKey9
        Case Asc(".")
        Case vbKeyBack
        Case Else
            KeyAscii = 0
    End Select

End Sub

Good Luck
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