Comment 4 for bug 1494336

Reviewed: https://review.openstack.org/222283
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=c89a4fdd88b0f8832b32af55f64e0d3a35c84388
Submitter: Jenkins
Branch: master

commit c89a4fdd88b0f8832b32af55f64e0d3a35c84388
Author: sridhargaddam <email address hidden>
Date: Thu Sep 10 16:14:13 2015 +0000

    Configure gw_iface for RAs only in Master HA Router

    For an HA Router which does not have any IPv6 subnets in the external network
    and when ipv6_gateway is not set, Neutron configures the gateway interface of
    the router to receive Router Advts for default route. In an HA router, only
    the Master instance has the IP addresses while the Backup instance does not
    have any addresses (including LLA). In Kernel version 3.10, when the last
    IPv6 address is removed from the interface, IPv6 proc entries corresponding
    to the iface are also deleted. This is however reverted in the later versions
    of kernel code.

    This patch addresses this issue by configuring the proc entry only for the
    Master HA Router instance instead of doing it un-conditionally.

    Closes-Bug: #1494336
    Change-Id: Ibf8e0ff64cda00314f8fa649ef5019c95c2d6004