Try
                    TempHost = Dns.GetHostEntry(SubnetAddr & i)
                    Form1.ListBox1.Invoke(New Form1.AddItemDelegate(AddressOf _
                      Form1.AddItem), New Object() {TempHost.HostName})
                Catch

        Dim t As System.Threading.Thread
        t = New System.Threading.Thread(AddressOf GetIP.GetAllIP)
        t.Start()