'**********************************
        Private Class PingAsyncArea
 
            Friend Sub StartTestArea(ByVal timeout As Integer)
                Dim ipAddress As String
                For n1 As Integer = 1 To 2
                    For n2 As Integer = 1 To 255
                        Dim test As PingAsync
                        ipAddress = "192.168." & n1 & "." & n2
                        test = New PingAsync(ipAddress, timeout)
                        AddHandler test.PingComplete, AddressOf PingComplete
                    Next n2
                Next n1
                Return
            End Sub
 
            Friend Sub StartTestArea(ByVal n1Start As Integer, ByVal n1End As _
              Integer, ByVal timeout As Integer)
                Dim ipAddress As String
                For n1 As Integer = n1Start To n1End
                    For n2 As Integer = 1 To 255
                        Dim test As PingAsync
                        ipAddress = "192.168." & n1 & "." & n2
                        test = New PingAsync(ipAddress, timeout)
                        AddHandler test.PingComplete, AddressOf PingComplete
                    Next n2
                Next n1
                Return
            End Sub
 
            Friend Sub StartTestArea(ByVal n1Start As Integer, ByVal n1End As _
              Integer, ByVal n2Start As Integer, ByVal n2End As Integer, ByVal _
              timeout As Integer)
                Dim ipAddress As String
                For n1 As Integer = n1Start To n1End
                    For n2 As Integer = n2Start To n2End
                        Dim test As PingAsync
                        ipAddress = "192.168." & n1 & "." & n2
                        test = New PingAsync(ipAddress, timeout)
                        AddHandler test.PingComplete, AddressOf PingComplete
                    Next n2
                Next n1
                Return
            End Sub
 
            Private Sub PingComplete(ByVal sender As Object, ByVal e As _
              System.Net.NetworkInformation.PingCompletedEventArgs)
                If e.Reply.Status = IPStatus.Success Then
                    mArrayNrIP += 1
                    Array.Resize(mArrayIP, mArrayIP.Length + 1)
                    mArrayIP(mArrayNrIP) = e.Reply.Address.ToString
                    mArrayNrDelay += 1
                    Array.Resize(mArrayDelay, mArrayDelay.Length + 1)
                    mArrayDelay(mArrayNrDelay) = e.Reply.RoundtripTime
                End If
                CType(sender, IDisposable).Dispose()
            End Sub
 
            '**********************************
            Private Class PingAsync
                Private WithEvents m_Ping As New Ping
 
                Public Event PingComplete(ByVal sender As Object, ByVal e As _
                  System.Net.NetworkInformation.PingCompletedEventArgs)
 
                Public Sub New(ByVal ip As String, ByVal timeout As Integer)
                    m_Ping.SendAsync(ip, timeout, ip)
                End Sub
 
                Private Sub m_PingComplete(ByVal sender As Object, ByVal e As _
                  System.Net.NetworkInformation.PingCompletedEventArgs) Handles _
                  m_Ping.PingCompleted
                    RaiseEvent PingComplete(sender, e)
                End Sub
            End Class 'PingAsync
 
        End Class 'PingArea
 
    End Module 'DoPingArea

Imports System.Net
Imports System.Net.NetworkInformation