Re: [PATCH net-next] ipv4/fib: send RTM_DELROUTE notify when flush fib

Hangbin Liu
2023-07-25T08:21:05Z

On Mon, Jul 24, 2023 at 08:48:20AM -0700, Stephen Hemminger wrote:
> On Mon, 24 Jul 2023 16:56:37 +0800
> Hangbin Liu <liuhangbin@gmail.com> wrote:
>
> > The NetworkManager keeps a cache of the routes. Missing/Wrong events mean that
> > the cache becomes inconsistent. The IPv4 will not send src route delete info
> > if it's bond to other device. While IPv6 only modify the src route instead of
> > delete it, and also no notify. So NetworkManager developers complained and
> > hope to have a consistent and clear notification about route modify/delete.
>
> Read FRR they get it right. The routing daemons have to track kernel,
> and the semantics have been worked out for years.

Yes, normally the routing daemon need to track kernel. On the other hand,
the kernel also need to make a clear feedback. The userspace developers may
not know the kernel code very well. The unclear/inconsistent notification
would make them confused.

Thanks
Hangbin