>
>So, I wonder if the kernel should remove the cloning routes when an
>interface goes down, and reinstall them when it goes up.  And then if
>it should do this on link detect events.  This is messy since on the
>upward transition there may be another route present.  So this might
>get into having them both present, with weights, and marking them
>inactive, etc., which is even more complicated.  (I realize this may
>be controversial and should perhaps be optional.)

This certainly bears thinking about.  I think that the entire question 
of how to behave in the presence or absence of carrier bears thought, 
such as my dhcp suggestion a couple of months ago.  We have more data; 
we should figure out how best to use it.

		--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb