Source : Free On-Line Dictionary of Computing

AARP probe packets
     
         {AARP} {packets} sent out on a nonextended
        {AppleTalk} network to discover whether a randomly selected
        node ID is being used by any node.  If not, the sending node
        uses the node ID.  If so, it chooses a different ID and sends
        more AARP probe packets.
     
        (1997-05-03)