I have Lubuntu 16.10 32bit and Chromium. I have configured iptables as follows:
iptables -I INPUT -p udp -m udp --dport 32768:61000 -j ACCEPT
ivan@ivan-HP-Lubuntu:~$ sudo iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- anywhere anywhere udp dpts:32768:61000
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
But I can't see any of my Chromecast devices. Any suggestion?