In article [ref] (at Wed, 30 Aug 2006 10:12:10 +1000), Herbert Xu [off-list ref] says:

Hasso Tepper [off-list ref] wrote:

quoted

quoted

You can disable it in /proc/sys/net/ipv6/conf/default/... and then
reenable it on the interfaces that you actually want.

You can't do that either (ie. reenable) in initscripts before link is up.

As soon as you do ifconfig ethX up it'll appear in /proc/sys and
you can reenable it.

The point is:

 - Until we have live address(es), we do not create inet6_dev{} for that
   device.
 - We do NOT run DAD until the link is ready (netif_carrier_ok()).

This means, we do NOT have any addresses until the link is once up,
and thus, because the sysctl entries live in inet6_dev{}, we do not
install net.ipv6.conf.ethX from values of net.ipv6.conf.default until
then.

Maybe, we can install inet6_dev{} without any IPv6 addresses when we
are bringing up the device before we start DAD.

--yoshfuji