Automatic ipv6 support?

[martinheidegger]

Currently we need to specify ip and interface.

throw new Error('For IPv6 multicast you must specify ip and interface')

But I am not sure why.

• ff0x::fb, the equivalent of 224.0.0.251, can be used as default address.
• ::/0, the equivalent of 0.0.0.0, can be used as default external interface.
• ::1, the equivalent of 127.0.0.1, can be used as default internal interface.

Couldn't extend those defaults for Ipv6 be used to enable IPv6 without a special interface definition?

Note: I just read that for ipv6, the interface needs to be a zone which could be assigned by using the interfaces name: ::%network_name

(reference: https://stackoverflow.com/questions/38448369/ipv6-multicast-with-node-js)

cc. @konobi

[RangerMauve]

The MDNSv6 RFC would be relevant here https://tools.ietf.org/html/rfc6762