7da4f601ee
ML2 provider networks partial specs let admins choose some provider network attributes and let neutron choose remaining attributes. This change provides the implementation for GRE/VXLAN provider networks. In practice, for GRE/VXLAN provider networks provider:segmentation_id choice can be delegated to neutron, in such case neutron will try to find a network in tenant network pools which respects provided provider attributes. DocImpact Related to blueprint provider-network-partial-specs Partial-Bug: #1330562 Change-Id: I720d7d04f6e3453145e888d9e4d9b5e381d0f7d4