.NET My.Computer.Network.Ping & PadLeft

Question

Following code snippet throws an error when padding the last part with 0, and the last part is 008, 009, 018, 019, 028, 029 etc. Anyone got an idea why?

Sub Main()
    Dim fixed As String = "192.168.0."
    Dim ip1, ip2 As String

    For i As Int32 = 1 To 255
        ip1 = fixed & Convert.ToString(i)
        Console.Write(ip1 & " - ")
        Try
            Console.WriteLine(My.Computer.Network.Ping(ip1))
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try

        ip2 = fixed & Convert.ToString(i).PadLeft(3, "0"c)
        Console.Write(ip2 & " - ")
        Try
            Console.WriteLine(My.Computer.Network.Ping(ip2))
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try
    Next
End Sub

Answer 1

Why are you padding it? I don't think you need the extra 0's.

Answer 2

I'd guess that the leading zero causes some subsystem to interpret the number as octal (an old C convention). 8 and 9 are invalid octal digits, so octal values with 8 and 9 in them would cause an error.