OT - Quagga/CARP

[Brad]

On Thu, Mar 16, 2006 at 09:52:07PM +0000, Bruce M Simpson wrote:
> On Thu, Mar 16, 2006 at 10:36:20PM +0100, Bart Van Kerckhove wrote:
> > ECMP was indeed one of the features i was looking for at that time, which i 
> > found to be impossible.
> > I just don't like the idea of moving towards another platform just for this 
> > reason, since I'm very happy with freebsd's performance.
> > There used to be a patch for ECMP, but it was a huge hack. very dirty at 
> > best.
> 
> itojun recently committed a set of ECMP related changes to OpenBSD.
> Unfortunately I have not had free time to review them in any detail.
> 
> I hope andre@ is watching this thread, it's probably on his laundry list too.
> I believe other parties may have implemented the hack you are referring to.
 
Heh. At first I read this and wasn't sure what ECMP was, I've never seen anyone
use that acronym before. The code Itojun commited to the OpenBSD tree consisted
of code to add multipath support for radix trees. The routing code still needs
to be modified to use this new support though.


radix tree with multipath support.  from kame.  deraadt ok
user visible changes:
- you can add multiple routes with same key (route add A B then route add A C)
- you have to specify gateway address if there are multiple entries on the table
  (route delete A B, instead of route delete A)
kernel change:
- radix_node_head has an extra entry
- rnh_deladdr takes extra argument

TODO:
- actually take advantage of multipath (rtalloc -> rtalloc_mpath)


http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/radix.c
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/net/radix_mpath.c