I thought I'd add a little to this community. This may have been done before but I searched and didn't see this code. It's not stellar or ground breaking but it is very useful for me.
I use this function to determine if a value passed is a valid IP address or not.
VB Code:
' Verifies if Data qualifies as an IP address
Function IsIP(IP As String) As Boolean
'Declarations
Dim tmpIP As Variant
Dim Element As Variant
Dim x As Integer, y As String
'Verify 4 octets
tmpIP = Split(IP, ".")
If UBound(tmpIP) <> 3 Then
IsIP = False
Exit Function
End If
'Verify all numerics
tmpIP = Replace(IP, ".", "")
For x = 1 To Len(tmpIP)
y = Mid(tmpIP, x, 1)
If Not IsNumeric(y) Then
IsIP = False
Exit Function
End If
Next x
'Verify octet values
tmpIP = Split(IP, ".")
For Each Element In tmpIP
If Element > 255 Then
IsIP = False
Exit Function
End If
Next
'All tests passed
IsIP = True
End Function