Virtualization allows for more efficient use of server resources by running multiple virtual machines on a single physical server. This is done through the use of a hypervisor which creates isolated virtual machines, each with their own operating system and applications. Networking in virtualized environments is enabled through software-defined networking which decouples the network control and forwarding functions from the underlying hardware, allowing for centralized programmatic control of network resources. Neutron is OpenStack's networking component that provides software-defined networking capabilities like network provisioning and virtual port management.

1. by Akanksha Agrawal and Sana Khan

3. A server is a collection of hardware
resources that are accessed by an OS
through specialized drivers.
These resources can be:
● CPU processor
● RAM (or memory)
● Storage
● Network Interface Card (NIC)

4. In a virtualized server:
● there is an added layer
called the Hypervisor.
● there are multiple isolated
VMs running its own
operating system and
applications.

5. ● Underutilization, inefficient usage of servers.
● Server Proliferation.
● Wastage of space, power, high costs of cooling the environment incurred by
the data centers.

6. ● Availability
● Virtualization results in a much better disaster recovery capability.
● Fault tolerance
● Ease in Migration
● Flexibility
● Huge decrease in the time it takes to provision new applications.
● Promote standardization.

7. ● Virtualization is a methodology of dividing the resources of a computer into
multiple execution environments.
● Virtualization decouples the application and operating system from the server
hardware.

10. ● Application based addressing is based on where that physical server is
located.
● The MAC address is associated with the physical server.

13. ● Create logical, virtual networks that are decoupled from the underlying
network hardware.
● Ensure the network can better integrate with and support increasingly virtual
environments.
● Creates a logical software-based view of the networking resources (switches,
routers, etc.)

14. Networking as a Service

15. ● Switching
● Routing
● Load Balancing ( LBaaS )
● Firewalling ( FWaaS )
● etc

16. ● Network (CRUD)
● Subnet (CRUD)
● Port (CRUD)

17. ● neutron net-create neutron subnet-create
● neutron net-list neutron subnet-list
● neutron net-update neutron subnet-show
● neutron net-delete neutron subnet-update
neutron subnet-delete
● neutron port-create
● neutron port-list
● neutron port-show
● neutron port-update
● neutron port-delete
http://docs.openstack.org/cli-reference/neutron.html

18. 1. Create a network.
2. Create a subnet and associate it with the network.
3. Boot the virtual machine instance and specify the network.
4. Nova interfaces with Neutron to create a port on the network.
5. Neutron assigns a MAC address and IP address to the newly created port
using attributes defined by the subnet.
6. Nova starts the instance.
7. The instance sends a DHCP request during boot, at which point, the DHCP
server responds with the IP address corresponding to the MAC address of the
instance.

19. The main components are:
● Neutron Server
● Plugins
● Plugin Agents
● Message Queue
● Database
● DHCP Agent
● L3 Agent

21. ● Neutron receives a request
to connect VM to a
new network.

23. ● Local
● Flat
● VLAN
● VXLAN

29. . . . the Switch/Router has to figure out what to do with the packet.
Switches and Routers have two logical planes of functions:
● Control Plane / Forwarding Plane: the logic that determines how traffic is
handled.
● Data Plane: the actual moving of packets from one network interface to
another.

30. ● In case of network changes, each device needs to be configured individually.
● Different vendors have different control plane logic.

31. ● Decouple the control plane (software) from the data plane (hardware).
● Provide centralized control and enjoy the benefits of a programmable
network.
● OpenFlow: protocol that allows centralized management to take place.

33. ● ovs-vsctl command (Configuring OpenvSwitch)
● ovs-ofctl command (Adding flow rules with OpenFlow)

34. ● SDN and NFV Simplified: A Visual Guide to Understanding Software Defined
Networks and Network Function Virtualization By: Jim Doherty
● OpenStack Networking Essentials By: James Denton
● Learning OpenStack Networking (Neutron) - Second Edition By: James
Denton