> The IPv6 feature isn’t link-local addresses, it’s being able to specify the interface to bind to as part of the address specification. This lets you demand that your IPv6-based tool use your wired Ethernet connection, for example.
I don’t think a design goal of IPv6 was to enable users to demand which link the kernel uses or open up some rich new world of link local ip services. I think it’s more like “because IPv6 hosts assign everything an address all at once, there’s a new problem when two interfaces use the same link local addresses since we can’t guarantee uniqueness so we have to invent this stupid zone_id convention to work around poor protocol design and implementation”. Design goals are different than constraints.
Have hosts put a guid in its LL address and print that on the sticker next to the mac address… idk. Actually it’d be nice if we only did link-exclusive things at the link layer, eh?