---
fixes:
  - |
    In before, creating a container with an existing Neutron port that has both
    ipv4 and ipv6 would fail. For example:

    $ docker run --net=dualnet -itd --name=container --ip 10.2.0.4 \
        --ip6 fe80::8 busybox

    ...
    docker: Error response from daemon: IpamDriver.RequestAddress: Requested ip address {'subnet_id': u'xxx', 'ip_address': u'fe80::8'} already belongs to a bound Neutron port: XXX.

    This was fixed in this release (Bug #1668803).