How to ping IP Adresses ?

Array.ForEach(Enumerable.Range(2, 255).ToArray(), i =>
               {
                   var reply = new Ping().Send(string.Format("102.168.1.{0}", i));
               });

Ping objPingSender = new Ping();
PingReply objPingReply = objPingSender.Send(strIpAddress);

 switch (objPingReply.Status)
 {
    case IPStatus.Success:
         return true;

    default:
        return false;
 }