Default route doesn't change to wireless device (ath0)

Jon Dama jd at
Thu Sep 8 15:13:08 PDT 2005

> > > > And whenever there is a wireless network available (where the system can log
> > > > in an get a network connection) the default route should be switched to that
> > > > wireless nic. Or even better, if both connections work, automatically choose
> > > > the faster one :-).
> > >
> > > That's the goal we're headed towards.  Unfortunatly, it's not an instant
> > > thing, particularly when people trying things like what you're doing
> > > that don't map well into the old world view of static devices that don't
> > > change networks.  The old model is wrong and has been so for quite some
> > > time, but that doesn't mean there aren't assumptions related to it all
> > > over the place.
> >
> > Again, the problem is with the routing code.  You should NOT need to be
> > deleting default routes simply because one link goes down and another
> > comes up on a different interface.
> >
> > Deleting the route simply because the interface went down is a hack.
> Got a new routing implemention handy?  Until then, well have to live
> with hacks. :(

True enough.  I think the general idea is that you need a two layer
routing table.  One that keeps tract of what is possible, and one that
keeps track of what is happening w.r.t existing flows.  Once an interface
link goes down, the route in the second table invaliadates and you go back
to the first to find a new route.

afaik, this is what is done in SunOS, on cisco hardware... MS might do it
too, certainly their handling of default routes meshes well with the
wireless world.

Some discussion of this on the dragonfly lists a while back.  I don't know
if anything became of it:

More information about the freebsd-current mailing list