Now that the trunk has been created and associated with a parent and sub-port, an instance can be booted and attached only to the parent port. Since a VIF is not being created for the subinterface(s), there's no need to attach them at boot. Logic within Neutron will associate traffic from sub-interfaces inside the instance with the parent interface.

The following OpenStack command syntax can be used to boot the instance with a parent port attached:

openstack server create 
--image <image> 
--flavor<flavor> 
--key-name <keypair name> 
--nic port-id=<parent port> 
<name>