Comment 7 for bug 1607412

Probably can be related to https://review.openstack.org/#/c/346221
"""
Avoid KeyError when accessing "dns_name" as it may not exist

Neutron LBaaS does not pass a full copy of the request_data
into this function, and causes the port create to fail
with a KeyError
"""

neutron/plugins/ml2/extensions/dns_integration.py
>> if not request_data[dns.DNSNAME]:

Same errors:
http://logs.openstack.org/21/346221/3/check/gate-grenade-dsvm-neutron-dvr-multinode/45c97d1/logs/new/screen-q-svc.txt.gz#_2016-07-25_20_37_27_173

2016-07-25 20:37:27.173 4591 INFO neutron.api.v2.resource [req-9e93d4e2-2a26-4053-ac05-dd1b4adf96af neutron -] create failed (client error): Unrecognized attribute(s) 'dns_name'