title: failed to bind port in openstack-neutron
body: <p>NOTE : I've seen this question and error being posted on different forums and in here, but none of them worked for me, and they belong to earlier versions of openstack. So, I posted a new question.</p>
  
  <p>I've been setting up OpenStack Train based on its installation documents, and after setting up services, I tried to create a selfservice network using the instructions <a href="https://docs.openstack.org/install-guide/launch-instance-networks-selfservice.html" rel="nofollow noreferrer">here</a> but in "Verify Operation" section, step number 3, I see all of the ports are down :</p>
  
  <pre><code>[root@dev-openstack-controller ~]# openstack port list
  +--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
  | ID                                   | Name | MAC Address       | Fixed IP Addresses                                                           | Status |
  +--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
  | 628ec286-90aa-4cca-92da-f698fb44a4e6 |      | fa:16:3e:a9:31:55 | ip_address='10.100.1.1', subnet_id='8d579a73-6951-445f-9905-51b9be2a6ff5'    | DOWN   |
  | bb77b0d9-7ea8-47d3-b951-139a7616a4bd |      | fa:16:3e:89:52:37 | ip_address='203.0.113.166', subnet_id='0666d21c-0fd9-4caf-b560-f7d11e50cd83' | DOWN   |
  | d2b684c9-eeee-47c4-ae12-dc97e19adf48 |      | fa:16:3e:cc:b8:3d | ip_address='10.100.1.2', subnet_id='8d579a73-6951-445f-9905-51b9be2a6ff5'    | DOWN   |
  | fb7aff87-d083-4ed2-bf82-2ab4393373c7 |      | fa:16:3e:c8:a7:95 | ip_address='203.0.113.101', subnet_id='0666d21c-0fd9-4caf-b560-f7d11e50cd83' | DOWN   |
  +--------------------------------------+------+-------------------+------------------------------------------------------------------------------+--------+
  </code></pre>
  
  <p>First, I don't know why I see 4 ports instead of 2, and second, when I check neutron logs, I get the following error, which says it fails to bind port :</p>
  
  <pre><code>2020-04-18 11:05:12.321 25009 INFO neutron.plugins.ml2.plugin [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Attempt 10 to bind port 628ec286-90aa-4cca-92da-f698fb44a4e6
  2020-04-18 11:05:12.347 25009 ERROR neutron.plugins.ml2.managers [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Port 628ec286-90aa-4cca-92da-f698fb44a4e6 does not have an IP address assigned and there are no driver with 'connectivity' = 'l2'. The port cannot be bound.
  2020-04-18 11:05:12.348 25009 ERROR neutron.plugins.ml2.managers [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Failed to bind port 628ec286-90aa-4cca-92da-f698fb44a4e6 on host dev-openstack-controller.ershandc.org for vnic_type normal using segments [{'network_id': 'ae2b1f57-d91a-4ecd-ad15-2cc4b51a376f', 'segmentation_id': 45, 'physical_network': None, 'id': 'c28112f0-4f07-4f23-9f89-c3e37e68054c', 'network_type': u'vxlan'}]
  </code></pre>
  
  <p>I also get the same error for flat networks as well :</p>
  
  <pre><code>2020-04-18 11:05:11.107 25009 INFO neutron.plugins.ml2.plugin [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Attempt 10 to bind port bb77b0d9-7ea8-47d3-b951-139a7616a4bd
  2020-04-18 11:05:11.135 25009 ERROR neutron.plugins.ml2.managers [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Port bb77b0d9-7ea8-47d3-b951-139a7616a4bd does not have an IP address assigned and there are no driver with 'connectivity' = 'l2'. The port cannot be bound.
  2020-04-18 11:05:11.136 25009 ERROR neutron.plugins.ml2.managers [req-5c9c16a4-2327-4f46-b0ab-84e4e128d783 - - - - -] Failed to bind port bb77b0d9-7ea8-47d3-b951-139a7616a4bd on host dev-openstack-controller.ershandc.org for vnic_type normal using segments [{'network_id': '25c5e314-e851-4a9c-ac7a-8e7b3e426deb', 'segmentation_id': None, 'physical_network': u'provider', 'id': '6dccf301-422b-41b9-b719-2999200126c6', 'network_type': u'flat'}]
  </code></pre>
  
  <p>I have tried different connectivities on ml2 plugin. Most of the cases relate to the following line in ml2_plugin.conf :</p>
  
  <pre><code>[ml2_type_flat]
  
  flat_networks = flat
  vni_ranges = 1:1000
  </code></pre>
  
  <p>Based on the openstack documentation, it should be <code>flat</code> but I've tried <code>*</code> as well and it didn't work.</p>
  
  <p>Can someone elaborate the problem for me? I'm installing on a CentOS 7 VM. Let me know if more information is needed.</p>