Title: dhcpcd 6.4.2 defaults to stable private IPv6 addresses
Author: William Hubbs <williamh@gentoo.org>
Content-Type: text/plain
Posted: 2014-07-17
Revision: 1
News-Item-Format: 1.0
Display-If-Installed: <=net-misc/dhcpcd-6.4.2

dhcpcd-6.4.2 and newer supports IPv6 stable private addresses when using
IPv6 stateless address autoconfiguration (SLAAC) as described in
RFC-7217 [1]. The configuration file shipped with dhcpcd activates this
feature by default, because it means that a machine cannot be tracked
across multiple networks since its address will no longer be based on
the hardware address of the interface.

We did receive a report in testing that IPv6 connectivity was lost due
to this change [2]. If you are concerned about losing IPv6 connectivity,
I recommend commenting out the line in dhcpcd.conf that says "slaac
private" when you upgrade.

See the references below for why the upstream default is to use private
addresses.

[1] http://tools.ietf.org/html/rfc7217
[2] https://bugs.gentoo.org/show_bug.cgi?id=514198
[3] http://tools.ietf.org/html/draft-ietf-6man-default-iids-00
[4] http://mail-index.netbsd.org/tech-net/2014/06/04/msg004572.html