Deep understanding of the OpenStack Network Architecture (II)

Original address: Https://blogs.oracle.com/ronen/entry/diving_into_openstack_network_architecture1

In the previous article, we learned about several network components, such as openvswitch/network namespace/linux bridges/veth pairs. In this article, we'll show you how these basic networking components work to implement OpenStack SDN solutions with 3 simple use case.
In these use case, we will understand the entire network configuration and how they run together. The use case is as follows: Creating a network-what happens when we create the network. How to create multiple isolated networks.
Create a virtual machine-once we have the network, we can create the virtual machine and connect it to the network.
The virtual machine's DHCP request--opensack can automatically configure the IP for the virtual machine. Completed via the OpenStack Neutron controlled DHCP service. Let's see how this service works, what DHCP requests and responses look like.

In this article, we'll show how the network connection works, and we'll see how the network packets go from a to B. Let's start by understanding what the network configuration has done. We then discuss how and when these network configurations were created. Personally, I think it's valuable to see how real web interfaces work and how to connect them through examples and concrete practices. Then, when everything comes to the truth, we know how the network connection works, and in the next article, I'll explain further how neutron configures these components to provide such network connectivity capabilities.

I recommend trying these examples in your own environment or using Oracle Openstack Tech Preview. A complete understanding of these network scenarios is very helpful for us to investigate network problems in the OpenStack environment. Use case #1: Create Network

The

Create network operation is very simple. We can do this using the GUI or the command line. OpenStack's network is only used by the tenants who created the network. Of course, if this network is "shared", it can also be used by all other tenants. A network can have multiple subnets, but for demonstration purposes and simplicity, we create only one subnet for every network. Create network:   from the command line;

[plain]  View plain  copy   # neutron net-create net1      Created& nbsp;a new network:      +---------------------------+---------------------------- ----------+      | field                      | Value                                  |      +---------------------------+-- ------------------------------------+      | admin_state_up             | True                                   |      | id                         |  5f833617-6179-4797-b7c0-7d420d84040c |      | name                       |  net1                                  |      | provider:network_type     | vlan                                   |      | provider: physical_network | default                               |      |  provider:segmentation_id  | 1000                                   |      | shared                     | False                                  |      | status                      |&nbSp active                                |      |  subnets                    |                                        |      | tenant_id                  | 9796e5145ee546508939cd49ad59d51f      |      +---------------------------+-------------------------- ------------+  
Create subnet for this network::

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