My understanding is that IPv6 expects a link-local IPv6 address to be configured for an ethernet interface for it to work. I'm finding in some cases it doesn't happen until a later time (after I'm trying to configure a static IPv6 address) or in some other cases, doesn't happen at all (yet IPv6 is working as I can successfully configure a static IPv6 address).

My question is, what tool is supposed to perform this configuration ... in general. I'm looking for an answer that is not specific to a particular distribution. Should the "ifconfig" command do this with some magic combination of options I don't see in the man page? Or should it be the "ip" command? Or is there some special tool for IPv6? Or some magic kernel incantation (obviously the kernel doesn't do it on its own).

FYI, I'm doing this on a network that has no IPv6 router and the static IPv6 addresses are Unique Local addresses (e.g. in fc00:/7).