Re: [patch net-next] bonding: create netlink event when bonding option is changed

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 20 Aug 2014 10:00:51 -0400
Andy Gospodarek <gospo@cumulusnetworks.com> wrote:

> > >
> > >My question was:  Is there a need for 2 netlink messages to indicate
> > >that a bonding configuration change was needed when the config came over
> > >netlink.  I did not see the need for 2 netlink messages in this case and
> > >was asking for clarification from you.  
> > 
> > Imagine 2 applications. One is just monitoring netlink events ("ip
> > mon"), the second is setting up bond via netlink. Now, the second sends
> > a message to kernel, that is unicast to kernel. The first application
> > does not see that message. Therefore there is need to generate the event
> > message in kernel and send it back to userspace via multicast.
> > That message the first application will see. And that is exactly what
> > my patch is doing.  
> 
> Agreed.  Thanks for having the discussion on this.
> 
> Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>

Quagga uses socket filter to solve this problem.
The application filters out it's own route change events.