[Dagger2]

Routing tables don't work here, because the routing table looks something like:

  fe80::/64 dev eth0 proto kernel metric 256 pref medium
  fe80::/64 dev eth0.11 proto kernel metric 256 pref medium
  fe80::/64 dev eth0.13 proto kernel metric 256 pref medium
  fe80::/64 dev eth0.14 proto kernel metric 256 pref medium
  fe80::/64 dev eth0.15 proto kernel metric 256 pref medium
  fe80::/64 dev eth0.16 proto kernel metric 256 pref medium

Which interface's fe80::4 are you talking about? They all have an fe80::4.

[gerdesj]

What do you do in IPv4 or 6 when the metric is the same?

That is literally the reason for the metric. You set it if you need your routes to be deterministic.

You need to direct your IP stack which routes are important to you - your IP stack cannot read your mind! You could use a routing protocol and daemon to do the job for you but someone needs to tell it how to work.