Comment 14 for bug 1709774

Hi Matthew,

I've looked at the server logs and they actually look like they are different subnets but the same network. The log snippet below shows two independent interfaces for two different subnets on the same network. This does match the heat template which is two subnets on the same 'mgmt_net' network.

2017-08-10 13:44:18.052 24945 DEBUG neutron.db.l3_dvr_db [req-30364b5a-5f17-4238-9422-4c83fec95878 - - - - -] Return the SNAT ports: defaultdict(<type 'list'>, {u'40846103-718c-443c-95c0-4a5f540844b7': [{'status': u'ACTIVE', 'binding:host_id': u'cloudcontrol', 'description': u'', 'allowed_address_pairs': [], 'extra_dhcp_opts': [], 'updated_at': '2017-08-10T20:44:15Z', 'device_owner': u'network:router_centralized_snat', 'revision_number': 7, 'port_security_enabled': False, 'binding:profile': {}, 'fixed_ips': [{'subnet_id': u'ebf5b419-9a50-4024-b613-4d310fc82015', 'ip_address': u'172.16.6.6'}], 'id': u'5543b3a8-a6a9-438f-965a-3ddfdea40412', 'security_groups': [], 'device_id': u'40846103-718c-443c-95c0-4a5f540844b7', 'name': u'', 'admin_state_up': True, 'network_id': u'b11c7c91-aea3-4200-a343-185d5220cc4d', 'tenant_id': u'', 'binding:vif_details': {u'port_filter': True, u'ovs_hybrid_plug': True}, 'binding:vnic_type': u'normal', 'binding:vif_type': u'ovs', 'mac_address': u'fa:16:3e:0d:d6:3f', 'project_id': u'', 'created_at': '2017-08-10T20:43:56Z'}, {'status': u'DOWN', 'binding:host_id': u'', 'description': u'', 'allowed_address_pairs': [], 'extra_dhcp_opts': [], 'updated_at': '2017-08-10T20:44:08Z', 'device_owner': u'network:router_centralized_snat', 'revision_number': 4, 'port_security_enabled': False, 'binding:profile': {}, 'fixed_ips': [{'subnet_id': u'83e49113-194a-4832-9075-0e14ff7aa0e0', 'ip_address': u'172.16.5.12'}], 'id': u'b0a8c228-79cb-40b3-84e9-52dfabab97ee', 'security_groups': [], 'device_id': u'40846103-718c-443c-95c0-4a5f540844b7', 'name': u'', 'admin_state_up': True, 'network_id': u'b11c7c91-aea3-4200-a343-185d5220cc4d', 'tenant_id': u'', 'binding:vif_details': {}, 'binding:vnic_type': u'normal', 'binding:vif_type': u'unbound', 'mac_address': u'fa:16:3e:4d:b1:63', 'project_id': u'', 'created_at': '2017-08-10T20:44:07Z'}]}) _get_snat_sync_interfaces /usr/lib/python2.7/site-packages/neutron/db/l3_dvr_db.py:549

So to clarify the bug report a bit, the problem arises with a DVR router attached to two subnets on the same neutron network.

When you perform the topology creation manually, does it instead result in one router interface with two IP addresses instead of two interfaces with one IP address each?