In article [ref] (at Tue, 30 Jan 2007 08:02:08 -0500), Neil Horman [off-list ref] says:

quoted

I do not think we should copy neighbor information from (one of)
default routers, but use temporary neigh entry (or neigh in new state)
for such datagrams in stead.  We should aware that:

Not sure how that is different from what I'm proposing.  a neighbor entry that
maps a given host on the current subnet to the MAC of the default router, that
then gets flushed when DAD completes is temporary, as far as I can see.

quoted

 1) default router's link-layer address may change.

True, but if this changes, all our network connectivity is lost, until the
normal neighbor solicitation process completes anyway.

No, router may update its link-layer address by NA with Override flag set.
In that case, we must use new link-layer for subsequent packets from
our opportunistic address duing DAD.

quoted

 2) we may have more than one default routers.

True, but I would think we could select any of them and this would work.
Granted, we wouldn't use all the default routers in the table as we would with
routed frames, but I'm not sure how we avoid that.

I mean, if the status of the selected default router has changed or 
has been deleted, we should try other router, at least.

quoted

 3) the default router's link-layer may be invalidated.

yes, but this would be bad for the same reason as (1)

We MUST take this into account.

--yoshfuji