Re: Detached address check

[Roy Marples <roy%marples.name@localhost>]

On 22/11/2017 17:18, Robert Swindells wrote:
> > So you don't want in kernel Duplicate Address Detection?
> > We already have sysctls to set the DaD packets sent to zero which
> > effectively addresses the TENTATIVE part. The above patch handles
> > DETACHED (well, for IPv4 anyway).
>
> I'm not in the habit of assigning duplicate IPv4 addresses so don't
> really care about DaD. That isn't the question that I'm asking though.
>
> I don't see why a router that isn't using stateless address autoconfig
> on a downstream interface should get the address of that interface set
> to DETACHED if the cable is unplugged.

But it's related.
If you want good DaD, and clearly you don't, there is a need to deny 
public use of the address before it's validated.

> Also, which RFC requires that IPv4 should follow the same protocol ?

RFC5227
https://tools.ietf.org/html/rfc5227

> > > If this change makes it into NetBSD-8 then I think you are going to
> > > spend a lot of time answering user questions.
> >
> > Well, the change has been in -current for over 2.5 years and I've not
> > spent much time either answering question or fixing bugs with it so I
> > disagree with that somewhat sweeping statement.
>
> The final change was only in September 2016, there are plenty of people
> still using NetBSD-7 on the mailing lists.
It's now November 2017 and there's a healthy amount of people posting to 
netbsd-current@ or tech-net@ their own special blend of problem running 
-current. I'm not really sure of your point here.

Roy