OpenStack Networking Overview

Original Address: http://docs.openstack.org/newton/install-guide-ubuntu/neutron-concepts.html

Networking Service Overview

OpenStack Networking (neutron) allows us to create network devices that are managed by other OpenStack service and add them to the Networking. The implementation of plug-in allows us to accommodate different types of network devices and software, and provides flexibility for Openstack's architecture and Deployment. It is composed of the following components:

neutron-server: Receive and route the appropriate API request to the appropriate OpenStack Networking plug-in for Processing.

OpenStack Networking plug-ins and agents: plug or unplug port, create a network or subnet and provide an IP address. But for a particular cloud, these plug-ins and agents are different because of the difference between the vendor and the technology Used. OpenStack Networking for Cisco virtual and physical switches, NEC OpenFlow products,open vswith,linux bridging, and VMware NSX Product provides Plug-ins and Agents.

Message Queue: Used by most OpenStack networking devices to route information between Neutron-server and various Agents. At the same time, it is used as a database to store specific Plug-ins networking State.

OpenStack Networking is primarily used to interact with OpenStack compute to provide network and connectivity to its instances

Networking (neutron) Concepts:

OpenStack Networking (neutron) manages all of the content in the OpenStack environment about virtual Networking Infrastructure (VNI) and physical Networking Infrastructure (PNI) Access Layer Content. OpenStack networking enables project to create an advanced virtual network topology that may include services such as Firewall,load balancer, and virtual private network (VPN).

Networking provides object abstraction such as Networks,subnets,routers. Each abstraction has the function of the corresponding physical device it mimics: networks contains subnets,routers for routing between different subnets and networks.

Any given networking setting contains at least one external Network. Unlike other network, the external network is more than just a virtual definition of the Network. instead, It represents a partial view of a physical external network that is accessible outside of OPENSTACK. The IP addresses in the external network can be accessed by any external networks.

In addition to the external network, each networking set up requires at least one or more internal Network. These software-defined networks connect directly to the VM. Only virtual machines in the same internal network, or subnets connected to the same router, can access the virtual machines in that Network.

In order to outside network and virtual machine can access each other. The routers between networks is a Must. Each of the router has a gateway connected to the external network, and one or more interface and internal networks are Connected. Like the physical router, the different subnets that connect to the same router are directly accessible to each other by the Machine. At the same time, the machine can access the outside network through the gateway on the Router.

In addition, we can assign the IP address on the external networks port to internal networks. No matter when, when there is something connected to the subnet, we call this connection as Port. We can connect the external network IP to the virtual machine via Port. In this way, the outside network can access the virtual Machine.

Networking also provides security groups. The security group allows administrators to define firewall rules for different group Definitions. A virtual machine can belong to one or more security Group. Networking imposes rules on these security group to limit the range or traffic type of blocked or non-blocking Ports,port to a virtual machine.

Each plug-in used by networking is different and has its own unique concept. This is not very important for manipulating Vni and OpenStack environments, But understanding these differences is useful for setting up networking. All networking will use a core plug-in and a security group plug-in (or just no-op security group plug-in). In addition, there are Firewall-as-a-service (FWaas) and Load-balancer-as-a-service (LBaas) plugin.

OpenStack Networking Overview