I need advise to create a simple port-scanner, who will need to detect if some specific devices are connected to the network from theire IP/MAC address. I am working on windows 7 and can use preferably C++ Builder 2010 Embarcadero, or java or Qt. The library have to be under a public domain or equivalent, as my software is a proprietary software. What library would you advice? Do you know any free software that I could start from, or any examples? What about using Indy Sockets or Synapse TCP/IP Librarys? Thanks in advance.