Lan?

Welcome to IPv6, the world of recursive WTFs!

There is no concept of "local" networks in IPv6, there is a notion of "on-link" networks. Which does not _necessarily_ correspond to the networks that are directly accessible in the same Ethernet collision domain.

That's because IPv6 uses multicasts instead of broadcasts for neighbor discovery, so you can have a multicast router bridging multiple Ethernet segments together. Just like proxy ARP in IPv4, but in IPv6 it's actually exposed to the host.

For an additional fun, on-link relations do not necessarily have to be transitive and they can have overlapping prefix lengths.

See: https://datatracker.ietf.org/doc/html/rfc5942 and https://datatracker.ietf.org/doc/html/rfc4943