Calculate IP in IP range - vb.net

Question

I have IP range string below:
Dim IPRange as String = "192.168.0.1-192.168.0.100"
I used code to count IP and add into Arraylist:
Dim beginIP() As Byte = IPAddress.Parse(IPRange.Split("-")(0)).GetAddressBytes
Array.Reverse(beginIP)
Dim endIP() As Byte = IPAddress.Parse(IPRange.Split("-")(1)).GetAddressBytes
Array.Reverse(endIP)
Dim IPbegin As UInt32 = BitConverter.ToUInt32(beginIP, 0)
Dim IPend As UInt32 = BitConverter.ToUInt32(endIP, 0)
Dim total as Integer = 0
Dim arr as New ArrayList()
For i As UInt32 = IPbegin To IPend
Dim IPbyte() As Byte = BitConverter.GetBytes(i)
Array.Reverse(IPbyte)
Dim IPCheck As String = New IPAddress(IPbyte).ToString
total += 1
arr.Add(IPCheck)
Next
But I have thousand IPRange like that with billion IP, loop make my application very slow. How can I speed up this code or another way to calculate IP range in this case?

Answer 1

Using your code
Dim stpw As Stopwatch = Stopwatch.StartNew
Dim IPRange As String = "192.168.0.0-192.200.255.255"
Dim beginIP() As Byte = IPAddress.Parse(IPRange.Split("-"c)(0)).GetAddressBytes
Array.Reverse(beginIP)
Dim endIP() As Byte = IPAddress.Parse(IPRange.Split("-"c)(1)).GetAddressBytes
Array.Reverse(endIP)
Dim IPbegin As UInt32 = BitConverter.ToUInt32(beginIP, 0)
Dim IPend As UInt32 = BitConverter.ToUInt32(endIP, 0)
Dim total As Integer = 0
For i As UInt32 = IPbegin To IPend
Dim IPbyte() As Byte = BitConverter.GetBytes(i)
Array.Reverse(IPbyte)
Dim IPCheck As String = New IPAddress(IPbyte).ToString
total += 1
Next
stpw.Stop()
Debug.WriteLine("{0:n0} in {1}", total, stpw.Elapsed)
with a larger range produced these results.
2,162,688 in 00:00:00.3756208