title: How to send ARP requests in C++
body: <p>I am new to programming on the Mac. I want to always insure that all network interfaces managed by my program have an MAC address for the GW in the ARP cache. To do this, I want to programmatically send an ARP request to the GW if I detect it's MAC address is missing.</p>
  
  <p>There doesn't seem to be support on Mac OS X for raw sockets on the AF_PACKET/PF_PACKET address family and protocol. Is there another way to do this in C++? For example, is there an API that can be used to send an ARP request?</p>