On Wed, Sep 24, 2014 at 9:31 AM, Nicolas Dichtel
[off-list ref] wrote:

quoted

I think in this case your ID's are still available, but aren't you
providing a new way
for the inner netns device to escape which we are trying to avoid?

It's why the ids depend on user ns. Only if user ns are the same we allow to
get an id for a peer netns.

Too late, userns is relatively new, relying on it breaks our existing
assumption.