Subject: Re: [PATCH RFC v2 net-next 00/25] rtnetlink: Add support for rigid checking of data in dump request

From: Stephen Hemminger <[email-masked]>
Date: Wed, 3 Oct 2018 07:59:09 -0700

On Mon,  1 Oct 2018 17:28:26 -0700
David Ahern <[email-masked]> wrote:

> How to resolve the problem of not breaking old userspace yet be able to
> move forward with new features such as kernel side filtering which are
> crucial for efficient operation at high scale?

What about forward compatibility? How would this work when running new iproute2
command on older kernels?

I expect the new command would set the "I am smart flag" and the older
kernel would ignore it. The if the header for the message type had
changed, the dump would be broken.