ipv6 support

[chris-beedie]

I am having an issue casting netflix from an android phone to newer generation chromecasts - gen1 work ok, however my gen3 and gen4 do not appear in the netflix app, but do in other apps (e.g. youtube).

From the firewall logs I can see a flurry of ipv6 multicast traffic on 5353 when opening netflix so I believe this is the issue. Neither blocking nor rejecting ipv6 udp traffic forces the chromecast to fallback to ipv4 unfortunately.

ipv6 support in udp broadcast relay would be amazing, is this planned? It seems like it will become more of a problem going forwards as more devices make use of ipv6 - I can also see my printer generating ipv6 multicasts, but not for functionality I need.

Thanks.