Raga_SDN_NSX_1

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Software Defined Networking(SDN)

Ranjith Kumar NPrincipal Software Engineer, EMC

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SDN-Definition

SDN is a network architecture that decouples the control and data planes, moving the control plane (network intelligence and policy making) to an application called a controller.

This migration of control, formerly tightly bound in individual network devices, into accessible computing devices enables the underlying infrastructure to be abstracted for applications and network services, which can treat the network as a logical or virtual entity

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Today’s Networks are Defined by the “Box”

• Hardware, Operating System, and Applications Built Into a “Box”.

• Too many RFC’s (above 6000rfc’s) • Mainframe Mentality• Operating a network is expensive– More than half the cost of a network– Yet, operator error causes most outages

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Why SDN

• Compute, storage and server technology is virtualized• Abstraction• It make network more responsive to dynamic

business condition• Centralized control• It allows easy in developing new protocol and test it• SDN allows you to specify “virtual topology” to cloud • SDN’s ability to virtualize the network

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Key drivers/use cases– Network Abstraction and Operator control– Automated provisioning of network bandwidth to

accommodate scheduled data transfers– Load balancing– Software based innovation– Better utilization of network path– Central configuration and intelligence provides – faster

convergence in case of failure

– Cloud computation -- Network Virtualization -- SDN

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Software Defined Networking (SDN)

API to the data plane(e.g., OpenFlow)

Logically-centralized control

Switches

Smart,slow

Dumb,fast

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WindowsWindows

x86

Virtualization

WindowsWindowsWindowsLinux

WindowsWindowsFreeBSD

Apps Apps Apps

Computer Industry

WindowsWindows

Virtualization

NetworkOS

WindowsWindowsNOXWindowsWindowsBeacon

Apps Apps Apps

Network Industry

Openflow

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Packet-Forwarding Hardware

Openflow Firmware

Packet-Forwarding Hardware

Openflow Firmware

Packet-Forwarding Hardware

Openflow Firmware

Packet-Forwarding Hardware

Openflow Firmware

Network Operating System

App App App App

Open Interfaceto Hardware(OpenFlow)

Open API

The “Software-Defined Network”

Two Key Definitions

• Data Plane: processing and delivery of packets– Based on state in routers and endpoints– E.g., IP, TCP, Ethernet, etc.– Fwding state + packet header forwarding decision

• Control Plane: establishing the state in routers– Determines how and where packets are forwarded– Routing, traffic engineering, firewall state, …– Centralized computation and configuration

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Control Plane in details

• Control plane need to address operator goal• Convey the configuration to network elements• Control plane must compute forwarding state:

-Consistent with particular low-level hardware/software -Based on entire network topology

• Control plane is implemented by controller– Controller can be software running on general purpose

hardware– Example Cisco One controller, Huawei SOX controller,

SNAC

Controller: Programmability

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Network OS

Controller Application

Events from switchesTopology changes,Traffic statistics,Arriving packets

Commands to switches(Un)install rules,Query statistics,Send packets

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Network Operating system

• The device operating system handles device operations like Boot, Flash, Memory management, OpenFlow Protocol handler, SNMP etc.

• Minimal source code, less resource and less cost• Collects information for global Network view• Conveys configuration from controller to

switches

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Packet Forwarder

Network OS

Global Network View

Abstract Network Model

Control Program

Network Virtualization

Software Defined Network - virtualizationSpecifies behavior

Compiles to topology

Transmits to switches

Packet Forwarder

Packet Forwarder

Packet Forwarder

Packet Forwarder

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Network Virtualization

– Introduces new abstraction layer for virtual topology

– Can have many virtual Networks – Solves VLAN limitation

– allows operator to express requirements and policies Via a set of logical switches and their configuration without binding to physical network

– Translates requirements into network elements

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Openflow• OpenFlow is designed to support policy-based flow

management within a network.• IP routers and Ethernet switches does initial forwarding lookup

using the devices CPU. After the initial lookup, the forwarding information is cached, and every subsequent packet utilizes the flow-cache for forwarding.

• OpenFlow makes a minor modification to above model by simply moving the initial lookup to a central server; every subsequent packet continues to use the local flow-cache for forwarding, just like networking devices have always worked.

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Traditional forwarding /Openflow forwarding

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RIB and FIB

• Routing Table at control Plane has many route to destination

• Forwarding table at Data Plane has best /valid route

• Open flow client at device level update FIB with help of firmware

• Table population- RIB FIB, Open Flow FIB

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Data-Plane: Simple Packet Handling

• Simple packet-handling rules– Pattern: match packet header bits– Actions: drop, forward, modify, send to controller – Counters: #bytes and #packets

1. src=1.2.*.*, dest=3.4.5.* drop 2. src = *.*.*.*, dest=3.4.*.* forward(2)3. src=10.1.2.3, dest=*.*.*.* send to controller

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SDN and Flow Table

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Networking Becomes Software-Oriented

• All complicated forwarding decision done in software • And control plane is a program (on a server)… , not a

protocol • We are programming the network, not designing it • Focus on modularity and abstractions• Innovation at software, not hardware, speeds • Software lends itself to clean abstractions

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Virtual Networks in IT infrastructure

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Network Virtualization Platform • Network Virtualization Platform (NVP) is software that operates

at the edge of any existing IP network and faithfully reproduces the entire networking environment in the virtual space.

• NVP transforms a physical network into a generalized pool of network capacity

• Virtual networks decouple from underlying network hardware• NVP creates an intelligent network edge managed by a control

cluster that transforms existing physical network into an IP backplane and enables the programmatic creation of 10s of thousands of agile virtual networks to connect workloads anywhere in your cloud

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Overview of Network Virtualization

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• Network virtualization enables Layer 2 to Layer 7 networking services in software

• NSX network virtualization programmatically creates, snapshots, deletes, and restores software-based virtual networks.

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Components of VMware NSX

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Data Plane• The NSX Data plane consists of the NSX

vSwitch. The vSwitch in NSX for vSphere is based on the vSphere Distributed Switch (VDS) (or Open vSwitch for non-ESXi hypervisors)

• The NSX vSwitch (VDS or OVS-based) abstracts the physical network

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Control Plane • The NSX control plane runs in the NSX

controller. In multihypervisor environment the controller nodes program the vSwitch forwarding plane.

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Management Plane • The NSX management plane is built by the NSX manager. • The NSX manager provides the single point of

configuration and the REST API entry-points in a vSphere environment for NSX

• Configure logical switches and connect virtual machines to these logical switches.

• It also provides API interface, which helps automate deployment and management of these switches through a Cloud management platform.

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Consumption Platform• The consumption of NSX can be driven directly via the

NSX manager UI. • The end-users tie in network virtualization to their

cloud management platform for deploying applications.

• NSX provides a rich set of integration into virtually any CMP via the REST API. Out of the box integration is also available through VMware vCloud Automation Center, vCloud Director and OpenStack.

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Virtual Network Services

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• Virtual Networks enables network services to be programmatically provisioned and accounted for on a per-port, per-hour basis.

• This allows network services to be dynamically provisioned on demand, and charged for on a pay-as-you-go basis.

• These layer4-7 services is used as building blocks for cloud service

Network Virtualization Platform

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Controller cluster

• The NVP Controller is a highly available clustered controller running on servers that manages all virtualized network components and connections.

• The controller cluster exposes the web services API and defines virtual networks.

• Capable of controlling and managing thousands of OVS edge devices(switching and routing modules)

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Logical switching

• Open vSwitch (OVS) is the core component on the intelligent edge.

• Each logical switch created is a separate L2 broadcast domain that can be associated with a separate subnet using a private IP space or public IP space(depending on logical networks).

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Logical Router

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• Logical routing supports both distributed and centralized routing

• In case of distributed router the NSX manager deploys the logical router control VM and pushes the Logical Interface configurations to each host through the controller cluster

• In the case of centralized routing, NSX manager just deploys the NSX Edge services router VM.

• Logical Router Control VM supports dynamic routing(OSPF/BGP) and pushes the learned routes to the Hypervisors through the controller cluster

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Q&A

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SDN final notes

• Express intent independent of implementation -Hardware (e.g., ASIC structure and capabilities) -Software (e.g., vendor-independent)

•OpenFlow is current proposal for forwarding -Standardized interface to switch -Configuration in terms of flow entries: <header, action>

•Design details concern exact nature of: -Header matching -Allowed actions

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Control Program

Software Defined Network -Basic

Packet forwarder

Packet forwarder

Packet forwarder

Packet forwarder

Packet forwarder

Network OS

Global Network View

Distributed algorithm running between neighbors

e.g. routing, access control