Chapter 12. VLAN-aware instances

12.1. Overview of VLAN-aware instances

Instances can send and receive VLAN-tagged traffic over a single vNIC. This is particularly useful for NFV applications (VNFs) that expect VLAN-tagged traffic, allowing a single vNIC to serve multiple customers or services.

For example, the tenant data network can use VLANs, or tunneling (VXLAN/GRE) segmentation, while the instances see the traffic tagged with VLAN IDs. As a result, network packets are tagged just before they are injected to the instance and do not need to be tagged throughout the entire network.

To implement VLAN-tagged traffic, create a parent port and attach the new port to an existing neutron network. When you attach the new port, OpenStack Networking adds a trunk connection to the parent port you created. Next, create subports. These subports connect VLANs to instances, which allow connectivity to the trunk. Within the instance operating system, you must also create a sub-interface that tags traffic for the VLAN associated with the subport.

12.2. Reviewing the trunk plug-in

During a Red Hat openStack deployment, the trunk plug-in is enabled by default. You can review the configuration on the controller nodes:

  • On the controller node, confirm that the trunk plug-in is enabled in the /var/lib/config-data/neutron/etc/neutron/neutron.conf file:

    service_plugins=router,qos,trunk

12.3. Creating a trunk connection

  1. Identify the network that requires the trunk port connection. This would be the network that will contain the instance that requires access to the trunked VLANs. In this example, this is the public network:

    openstack network list
    +--------------------------------------+---------+--------------------------------------+
    | ID                                   | Name    | Subnets                              |
    +--------------------------------------+---------+--------------------------------------+
    | 82845092-4701-4004-add7-838837837621 | private | 434c7982-cd96-4c41-a8c9-b93adbdcb197 |
    | 8d8bc6d6-5b28-4e00-b99e-157516ff0050 | public  | 3fd811b4-c104-44b5-8ff8-7a86af5e332c |
    +--------------------------------------+---------+--------------------------------------+
  2. Create the parent trunk port, and attach it to the network that the instance connects to. In this example, create a neutron port named parent-trunk-port on the public network. This trunk is the parent port, as you can use it to create subports.

    openstack port create --network public parent-trunk-port
    +-----------------------+-----------------------------------------------------------------------------+
    | Field                 | Value                                                                       |
    +-----------------------+-----------------------------------------------------------------------------+
    | admin_state_up        | UP                                                                          |
    | allowed_address_pairs |                                                                             |
    | binding_host_id       |                                                                             |
    | binding_profile       |                                                                             |
    | binding_vif_details   |                                                                             |
    | binding_vif_type      | unbound                                                                     |
    | binding_vnic_type     | normal                                                                      |
    | created_at            | 2016-10-20T02:02:33Z                                                        |
    | description           |                                                                             |
    | device_id             |                                                                             |
    | device_owner          |                                                                             |
    | extra_dhcp_opts       |                                                                             |
    | fixed_ips             | ip_address='172.24.4.230', subnet_id='dc608964-9af3-4fed-9f06-6d3844fb9b9b' |
    | headers               |                                                                             |
    | id                    | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39                                        |
    | mac_address           | fa:16:3e:33:c4:75                                                           |
    | name                  | parent-trunk-port                                                           |
    | network_id            | 871a6bd8-4193-45d7-a300-dcb2420e7cc3                                        |
    | project_id            | 745d33000ac74d30a77539f8920555e7                                            |
    | project_id            | 745d33000ac74d30a77539f8920555e7                                            |
    | revision_number       | 4                                                                           |
    | security_groups       | 59e2af18-93c6-4201-861b-19a8a8b79b23                                        |
    | status                | DOWN                                                                        |
    | updated_at            | 2016-10-20T02:02:33Z                                                        |
    +-----------------------+-----------------------------------------------------------------------------+
  3. Create a trunk using the port that you created in step 2. In this example the trunk is named parent-trunk.

    openstack network trunk create --parent-port parent-trunk-port parent-trunk
    +-----------------+--------------------------------------+
    | Field           | Value                                |
    +-----------------+--------------------------------------+
    | admin_state_up  | UP                                   |
    | created_at      | 2016-10-20T02:05:17Z                 |
    | description     |                                      |
    | id              | 0e4263e2-5761-4cf6-ab6d-b22884a0fa88 |
    | name            | parent-trunk                         |
    | port_id         | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39 |
    | revision_number | 1                                    |
    | status          | DOWN                                 |
    | sub_ports       |                                      |
    | tenant_id       | 745d33000ac74d30a77539f8920555e7     |
    | updated_at      | 2016-10-20T02:05:17Z                 |
    +-----------------+--------------------------------------+
  4. View the trunk connection:

    openstack network trunk list
    +--------------------------------------+--------------+--------------------------------------+-------------+
    | ID                                   | Name         | Parent Port                          | Description |
    +--------------------------------------+--------------+--------------------------------------+-------------+
    | 0e4263e2-5761-4cf6-ab6d-b22884a0fa88 | parent-trunk | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39 |             |
    +--------------------------------------+--------------+--------------------------------------+-------------+
  5. View the details of the trunk connection:

    openstack network trunk show parent-trunk
    +-----------------+--------------------------------------+
    | Field           | Value                                |
    +-----------------+--------------------------------------+
    | admin_state_up  | UP                                   |
    | created_at      | 2016-10-20T02:05:17Z                 |
    | description     |                                      |
    | id              | 0e4263e2-5761-4cf6-ab6d-b22884a0fa88 |
    | name            | parent-trunk                         |
    | port_id         | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39 |
    | revision_number | 1                                    |
    | status          | DOWN                                 |
    | sub_ports       |                                      |
    | tenant_id       | 745d33000ac74d30a77539f8920555e7     |
    | updated_at      | 2016-10-20T02:05:17Z                 |
    +-----------------+--------------------------------------+

12.4. Adding subports to the trunk

  1. Create a neutron port.

    This port is a subport connection to the trunk. You must also specify the MAC address that you assigned to the parent port:

    openstack port create --network private --mac-address fa:16:3e:33:c4:75 subport-trunk-port
    +-----------------------+--------------------------------------------------------------------------+
    | Field                 | Value                                                                    |
    +-----------------------+--------------------------------------------------------------------------+
    | admin_state_up        | UP                                                                       |
    | allowed_address_pairs |                                                                          |
    | binding_host_id       |                                                                          |
    | binding_profile       |                                                                          |
    | binding_vif_details   |                                                                          |
    | binding_vif_type      | unbound                                                                  |
    | binding_vnic_type     | normal                                                                   |
    | created_at            | 2016-10-20T02:08:14Z                                                     |
    | description           |                                                                          |
    | device_id             |                                                                          |
    | device_owner          |                                                                          |
    | extra_dhcp_opts       |                                                                          |
    | fixed_ips             | ip_address='10.0.0.11', subnet_id='1a299780-56df-4c0b-a4c0-c5a612cef2e8' |
    | headers               |                                                                          |
    | id                    | 479d742e-dd00-4c24-8dd6-b7297fab3ee9                                     |
    | mac_address           | fa:16:3e:33:c4:75                                                        |
    | name                  | subport-trunk-port                                                       |
    | network_id            | 3fe6b758-8613-4b17-901e-9ba30a7c4b51                                     |
    | project_id            | 745d33000ac74d30a77539f8920555e7                                         |
    | project_id            | 745d33000ac74d30a77539f8920555e7                                         |
    | revision_number       | 4                                                                        |
    | security_groups       | 59e2af18-93c6-4201-861b-19a8a8b79b23                                     |
    | status                | DOWN                                                                     |
    | updated_at            | 2016-10-20T02:08:15Z                                                     |
    +-----------------------+--------------------------------------------------------------------------+
    Note

    If you receive the error HttpException: Conflict, confirm that you are creating the subport on a different network to the one that has the parent trunk port. This example uses the public network for the parent trunk port, and private for the subport.

  2. Associate the port with the trunk (parent-trunk), and specify the VLAN ID (55):

    openstack network trunk set --subport port=subport-trunk-port,segmentation-type=vlan,segmentation-id=55 parent-trunk

12.5. Configuring an instance to use a trunk

You must configure the instance operating system to use the MAC address that neutron assigned to the subport. You can also configure the subport to use a specific MAC address during the subport creation step.

  1. Review the configuration of your network trunk:

    $ openstack network trunk list
    +--------------------------------------+--------------+--------------------------------------+-------------+
    | ID                                   | Name         | Parent Port                          | Description |
    +--------------------------------------+--------------+--------------------------------------+-------------+
    | 0e4263e2-5761-4cf6-ab6d-b22884a0fa88 | parent-trunk | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39 |             |
    +--------------------------------------+--------------+--------------------------------------+-------------+
    
    
    $ openstack network trunk show parent-trunk
    +-----------------+------------------------------------------------------------------------------------------------+
    | Field           | Value                                                                                          |
    +-----------------+------------------------------------------------------------------------------------------------+
    | admin_state_up  | UP                                                                                             |
    | created_at      | 2016-10-20T02:05:17Z                                                                           |
    | description     |                                                                                                |
    | id              | 0e4263e2-5761-4cf6-ab6d-b22884a0fa88                                                           |
    | name            | parent-trunk                                                                                   |
    | port_id         | 20b6fdf8-0d43-475a-a0f1-ec8f757a4a39                                                           |
    | revision_number | 2                                                                                              |
    | status          | DOWN                                                                                           |
    | sub_ports       | port_id='479d742e-dd00-4c24-8dd6-b7297fab3ee9', segmentation_id='55', segmentation_type='vlan' |
    | tenant_id       | 745d33000ac74d30a77539f8920555e7                                                               |
    | updated_at      | 2016-10-20T02:10:06Z                                                                           |
    +-----------------+------------------------------------------------------------------------------------------------+
  2. Create an instance that uses the parent port-id as its vNIC:

    nova boot --image cirros --flavor m1.tiny testInstance --security-groups default --key-name sshaccess --nic port-id=20b6fdf8-0d43-475a-a0f1-ec8f757a4a39
    
    
    +--------------------------------------+-----------------------------------------------+
    | Property                             | Value                                         |
    +--------------------------------------+-----------------------------------------------+
    | OS-DCF:diskConfig                    | MANUAL                                        |
    | OS-EXT-AZ:availability_zone          |                                               |
    | OS-EXT-SRV-ATTR:host                 | -                                             |
    | OS-EXT-SRV-ATTR:hostname             | testinstance                                  |
    | OS-EXT-SRV-ATTR:hypervisor_hostname  | -                                             |
    | OS-EXT-SRV-ATTR:instance_name        |                                               |
    | OS-EXT-SRV-ATTR:kernel_id            |                                               |
    | OS-EXT-SRV-ATTR:launch_index         | 0                                             |
    | OS-EXT-SRV-ATTR:ramdisk_id           |                                               |
    | OS-EXT-SRV-ATTR:reservation_id       | r-juqco0el                                    |
    | OS-EXT-SRV-ATTR:root_device_name     | -                                             |
    | OS-EXT-SRV-ATTR:user_data            | -                                             |
    | OS-EXT-STS:power_state               | 0                                             |
    | OS-EXT-STS:task_state                | scheduling                                    |
    | OS-EXT-STS:vm_state                  | building                                      |
    | OS-SRV-USG:launched_at               | -                                             |
    | OS-SRV-USG:terminated_at             | -                                             |
    | accessIPv4                           |                                               |
    | accessIPv6                           |                                               |
    | adminPass                            | uMyL8PnZRBwQ                                  |
    | config_drive                         |                                               |
    | created                              | 2016-10-20T03:02:51Z                          |
    | description                          | -                                             |
    | flavor                               | m1.tiny (1)                                   |
    | hostId                               |                                               |
    | host_status                          |                                               |
    | id                                   | 88b7aede-1305-4d91-a180-67e7eac8b70d          |
    | image                                | cirros (568372f7-15df-4e61-a05f-10954f79a3c4) |
    | key_name                             | sshaccess                                     |
    | locked                               | False                                         |
    | metadata                             | {}                                            |
    | name                                 | testInstance                                  |
    | os-extended-volumes:volumes_attached | []                                            |
    | progress                             | 0                                             |
    | security_groups                      | default                                       |
    | status                               | BUILD                                         |
    | tags                                 | []                                            |
    | tenant_id                            | 745d33000ac74d30a77539f8920555e7              |
    | updated                              | 2016-10-20T03:02:51Z                          |
    | user_id                              | 8c4aea738d774967b4ef388eb41fef5e              |
    +--------------------------------------+-----------------------------------------------+

12.6. Understanding trunk states

  • ACTIVE: The trunk is working as expected and there are no current requests.
  • DOWN: The virtual and physical resources for the trunk are not in sync. This can be a temporary state during negotiation.
  • BUILD: There has been a request and the resources are being provisioned. After successful completion the trunk returns to ACTIVE.
  • DEGRADED: The provisioning request did not complete, so the trunk has only been partially provisioned. It is recommended to remove the subports and try again.
  • ERROR: The provisioning request was unsuccessful. Remove the resource that caused the error to return the trunk to a healthier state. Do not add more subports while in the ERROR state, as this can cause more issues.