How to find a free port in C#?

using System.Net.NetworkInformation
private string FreeTcpPort(int iStart, int iEnd)
{

 int iFreePort = 0;
 int iStartRange = iStart;
 int iEndRange = iEnd;
 IPGlobalProperties properties = IPGlobalProperties.GetIPGlobalProperties();
 IPEndPoint[] tcpEndPoints = properties.GetActiveTcpListeners();

List<int> iPortsinUse= tcpEndPoints.Select(p => p.Port).ToList<int>();


for (int port = iStartRange; port < iEndRange; port++)
 {
 if (!iPortsinUse.Contains(port))
 {
   iFreePort = port;
   break;
 }
 }
 return iFreePort.ToString();
}

Below code requests first open port from the given range

FreeTcpPort(2000,3000)

How to find a port which are being used or not in Windows OS?

netstat -an | find ":portno"

Example: find a port no 2000 is in use.  If its not in use then return empty value otherwise it return "LISTENTING" as mentioned below

netstat -an | find ":2000"
 TCP    127.0.0.1:2000         0.0.0.0:0              LISTENING

How to see the statistics (how many packets received, sent, discard) of the bounded IP in a machine using C#?

using System.Net.NetworkInformation
private void IPDetails()
{
 IPGlobalProperties properties = IPGlobalProperties.GetIPGlobalProperties();
 IPGlobalStatistics ipDetails = properties.GetIPv4GlobalStatistics();
 Console.WriteLine(" Inbound Packet Data:");
 Console.WriteLine(" Received packets: {0}", ipDetails.ReceivedPackets);
 Console.WriteLine(" Forwarded packets: {0}", ipDetails.ReceivedPacketsForwarded);
 Console.WriteLine(" Delivered packets: {0}", ipDetails.ReceivedPacketsDelivered);
 Console.WriteLine(" Discarded packets: {0}", ipDetails.ReceivedPacketsDiscarded);
}