On Wed, Dec 31, 2003 at 04:31:14AM +1100, Darren Reed wrote:
> What really needs to happen is for the routing code to support multiple
> routes to the same destination (as a starting point!) and be able to
> select one based on some sort of path cost.

The RADIX_MPATH feature in KAME is a good starting point for multiple
routes to the same destination.  The feature is not quite complete:

  * When a destination has both a link-local route and a gateway
    route on the same link, then RADIX_MPATH should ordinarily prefer
    the gateway route, with setsockopt(,SO_DONTROUTE,) forcing the
    link-local route.

  * RADIX_MPATH does not use multiple paths for UDP packets very
    effectively because of route caching.

  * RADIX_MPATH will try to give 1/Nth the traffic to each of N
    routes. The route metric does not even enter the picture.

(BTW, NetBSD is hamstrung as a wireless IP router by its inability to
keep both a local and a remote route to the same host. It is common
in a wireless network that the "best" route to a neighbor is not the
shortest route.)

Dave

-- 
David Young             OJC Technologies
dyoung@ojctech.com      Urbana, IL * (217) 278-3933