Subject: Re: [RFC PATCH] net: ipv6: Make address flushing on ifdown optional

From: David Ahern <[email-masked]>
Date: Tue, 27 Jan 2015 20:21:58 -0700

On 01/27/2015 08:28 AM, Hannes Frederic Sowa wrote:
>>   From the discussion a second patch is needed to make sure DAD is done
>> on a link up if there is an address configured.
>
> Thank you!
>
> Let's see if the DAD patch isn't complex, maybe it is a candidate for
> stable?

Actually, DAD is done on a link up; you can see the notifications go out 
when the link is brought up:

18:46:28.519907 IP6 :: > ff02::1:ff00:10: ICMP6, neighbor solicitation, 
who has 2001:1::10, length 24
18:46:28.607650 IP6 :: > ff02::1:ff03:402: ICMP6, neighbor solicitation, 
who has fe80::1:2ff:fe03:402, length 24

So current top of tree works fine wrt DAD on addresses added when a link 
is down and then the link is brought up.

But, my previous patch does not re-send notifications on the up in a 
down-up cycle. I believe it is because the IFA_F_TENTATIVE flag is not 
set for the global address configured. I will address that in the 
revised patch.

David