C#

int threads = 200;
List<system.net.sockets.tcpclient> clientList = new List<system.net.sockets.tcpclient>(threads);
List<iasyncresult> resultList = new List<iasyncresult>();

for (int i = 0; i < threads; i++)
{
System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
IAsyncResult result = null;
try
{
	result = client.BeginConnect(testedHost, testedPort, null, null);
}
catch
{
}
clientList.Add(client);
resultList.Add(result);
}

for (int i = 0; i < threads; i++)
{
try
{
	clientList[i].EndConnect(resultList[i]);
	clientList[i].Close();
}
catch
{
	//processint the result and determining if tested host is alive or not
}

}
</iasyncresult></iasyncresult></system.net.sockets.tcpclient></system.net.sockets.tcpclient>