ARP Scout
Wait for a network device to come online and run an associated script
ARP Scout is a program that will run a script once when a device on your network comes online.
Once it comes online it will keep tabs on the device and after a certain time out period it will run the script with the stop argument.
ARP Scout monitors either the Linux Proc file system for changes in the the ARP cache or will use PCAP to watch for new MAC and IP address combinations.