by Akanksha Agrawal and Sana Khan

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)

In a virtualized server:

● there is an added layer called the Hypervisor.

● there are multiple isolated VMs running its own operating system and applications.

● Underutilization, inefficient usage of servers.

● Server Proliferation.

● Wastage of space, power, high costs of cooling the environment incurred by

the data centers.

● 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.

● 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.

● Application based addressing is based on where that physical server is located.

● The MAC address is associated with the physical server.

● 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.)

Networking as a Service

● Switching

● Routing

● Load Balancing ( LBaaS )

● Firewalling ( FWaaS )

● etc

● Network (CRUD)

● Subnet (CRUD)

● Port (CRUD)

● 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

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.

The main components are:

● Neutron Server● Plugins● Plugin Agents● Message Queue● Database● DHCP Agent● L3 Agent

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

● Local

● Flat

● VLAN

● VXLAN

. . . 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.

● In case of network changes, each device needs to be configured individually.

● Different vendors have different control plane logic.

● 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.

● ovs-vsctl command (Configuring OpenvSwitch)

● ovs-ofctl command (Adding flow rules with OpenFlow)

● 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