Description of problem: When using IPv6 tenant networks, the compute node will detect the IPv6 router announcements (RAs) from Neutron, which poisons the IPv6 route tables. Version-Release number of selected component (if applicable): OSP 7.3 Beta How reproducible: 100% Steps to Reproduce: 1. Deploy overcloud 2. Create IPv6 tenant networks 3. Add a router to the network 4. Start an instance on the network Actual results: The qbr interface accepts the RA from the Neutron router, and the default route for IPv6 gets set to the Neutron router. Expected results: The compute nodes should ignore RAs on the OVS bridges Additional info: In order to turn this behavior on/off, you can edit /proc/sys/net/ipv6/conf/default/accept_ra to be "0" instead of "1". You can also turn it on/off on a per-interface basis, e.g.: echo "1" > /proc/sys/net/ipv6/conf/eth0/accept_ra This needs to be tested, so we can determine if RAs will still be accepted on interfaces configured with IPv6, or if we need to set accept_ra to "1" for the individual interfaces.
There is a downstream review of the changes needed to fix this bug here: https://code.engineering.redhat.com/gerrit/#/c/67206/ I tested it, and it appears to work.
followup after irc chat just now about where this fix lands: the fix for this bug is included in the fix for bug 1303758 (links to gerrit above the description) - from that bug I can see it is in "Fixed In Version: openstack-tripleo-heat-templates-0.8.6-117.el7ost"
[root@overcloud-compute-0 ~]# cat /proc/sys/net/ipv6/conf/default/accept_ra 0
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-0264.html