Re: [PATCH net-next v2 0/2] net: ipv6: Improve user experience with multipath routes

[David Miller <davem@davemloft.net>]

From: David Ahern <dsa@cumulusnetworks.com>
Date: Thu, 26 Jan 2017 10:26:51 -0700

> On 1/26/17 7:58 AM, Nicolas Dichtel wrote:
>> Le 24/01/2017 à 17:06, David Miller a écrit :
>>> From: David Ahern <dsa@cumulusnetworks.com>
>>> Date: Fri, 20 Jan 2017 12:31:44 -0700
>>>
>>>> BTW, I am in favor of not requiring a user API for this but just
>>>> doing it. I can't imagine anyone working with multipath routes not
>>>> wanting the efficiency of the RTA_MULTIPATH attribute. These patches
>>>> require an API only because of the rule not to break userspace. If
>>>> we conclude to just do it without an API, the multipath_add and
>>>> multipath_del need to be modified to only send a notification once
>>>> at the end of the actions.
>>>
>>> After some consideration, I agree.
>> Sorry for my late reply but I fear that this will break some userland apps like
>> quagga.
> 
> Quagga does not properly handle IPv6 multipath routes received from
> the kernel. I checked this with debian/jessie version and our
> version, and Donald reviewed the source. It is broken.

If this is true, quagga is asbolutely not an argument for this "breaking"
something.  It doesn't break anything.