好的記性 不如 爛的筆記

Openstack的網路規劃。

1. Management Network : 用於Openstack內部管理使用，如各種服務之間的通訊。
2. VM(Tenant Network) : Opentstack部屬的VM所使用的網路。
在現在的openstack (ocata)，Management 已經與 Tenant 合併。
3. External Network : 一般來說，Management Network是內部私有網路。只用於MVM之間的通訊，與其他非VM網路是有隔離的。External network是透過 controller對外連接，Neutron V3的服務讓 VM能對外連線。

Openstack Networking service可分為2種。

• 1.Provider networks
• 2.Self-service networks

The provider networks option deploys the OpenStack Networking service in the simplest way possible with primarily layer-2 (bridging/switching) services and VLAN segmentation of networks. Essentially, it bridges virtual networks to physical networks and relies on physical network infrastructure for layer-3 (routing) services. Additionally, a DHCP service provides IP address information to instances

Provider networks
Provider network是最簡單的方式部屬Openstack的服務，其中只會用到 layer2(bridging/switching)的網路架構。
他單純是將VM通通bridge到實體網路。依靠外網的L3的service。
已下是 Provider Networks的內部原件。

Self service

The self-service networks option augments the provider networks option with layer-3 (routing) services that enable self-service networks using overlay segmentation methods such as VXLAN. Essentially, it routes virtual networks to physical networks using NAT. Additionally, this option provides the foundation for advanced services such as LBaaS and FWaaS

Self-service 搭配provider一起使用，並且使用vxlan。
在內網間使用NAT來連接虛擬網路與實體網路。

Provider Network實際上的結構圖

https://docs.openstack.org/ocata/install-guide-ubuntu/launch-instance-networks-provider.html

Self-service network結構圖

https://docs.openstack.org/ocata/install-guide-ubuntu/launch-instance-networks-selfservice.html

會盡可能的詳細說明