Quote from: Patrick M. Hausen on January 02, 2026, 01:32:52 AMQuote from: Maurice on January 02, 2026, 01:27:15 AMThis is simply unsupported in the real world. You can't have multiple default routers which advertise different SLAAC prefixes in the same LAN.
I noticed that "in the real world" but still this comes as quite the surprise to me. Because all the IPng/IPv6 fundamentals textbooks I read more than a decade ago said that is how it's supposed to work. Multihoming - solved. An arbitrary number of addresses/prefixes on every host interface plus router advertisements will just do the right thing.
So like the OP I took it as a given that this setup should "just work".
But then again at some point in time host to host IPsec was mandatory for any compliant IPv6 implementation, too ...