i have my rokus check in by having them listen on a udp port for a text string. when my server sends the the text string. it is recieved by the player then broadcasts its unique dev ID back to my server.
server command to send string: echo "pingall" | nc -u 192.168.1.255 2222
server command to listen for response and store in a file: nc -w 10 -l -u 192.168.1.1 2223 >/tmp/rokus.tmp