Author Archives: LF Research

What is Cisco SDN or ACI?

Cisco SDN or ACI provides a way to run and manage the network in a faster and better way. It is a centralized approach for provisioning, managing, promoting and programming the infrastructure of the network which is abstracted from the applications.

Working

Cisco ACI accumulates both hardware and software and is a policy-driven solution. The hardware comprises Cisco Nexus 9000 switches. The software for Application Centric Infrastructure includes:

• Data Center Pod
• Data Center Policy Engine
•  Virtual and Physical Leaf Switches(Non-Directly Attached).

The Network of Cisco ACI is same as that of deployed by the data centers for the past few years with slight changes. Only some protocols and management policy is changed for the underlying infrastructure.

For handling the workloads in the network equal-cost multi-path (ECMP) routing is used along with overlay protocols between two endpoints like VXLAN virtual extensible local area network. It can handle the workload of networks present anywhere. This will allow the network to have virtual or physical machines in the same layer (layer 2).

Cisco ACI provides a path to support:

• VLAN
• VXLAN
• Network virtualization generic routing encapsulation (NV-GRE)

NV-GRE creates a logical domain.

The SDN Controller of the ACI has, the Application Policy Infrastructure Controller (APIC) which is responsible for managing and configuring the policy of the ACI switches. No configuration is stick to the device making hardware stateless. This stateless computing model is used by the Application Policy Infrastructure Controller for deploying and re-deploying hardware. It acts as a central repository.

Cisco SDN or ACI provides other services for the data center or cloud environment. APIC, can integrate:

• Advanced security.
• Load balancing.
• Monitoring.

There are many products which can be integrated with the ACI like:

• Sourcefire
• Embrane
• F5
• Cisco ASA
• Citrix

To integrate with cloud northbound APIs are used on the API Controller.

Integration with Other Products

                                                                         Source: SDX

To know each detail of ACI refer to the Logic Finder course

https://www.logicfinder.net/wp-content/uploads/2019/02/Course-17-Cisco-ACI-outline.pdf

A software-defined data center virtualizes network, storage, and CPU and delivers it as a service. The virtualization techniques are used for implementing hardware infrastructure into VMs. Hardware is abstracted for deployment, provisioning, and configuration. Software intelligence is used for this abstraction.

SDDC is not common in practice due to its novice techniques but is adopted by big enterprises and providers like Amazon, Google, and Open Compute Project.

SDDC Components

There are three main components of SDDC which are:

• Network virtualization

Network Virtualization is a component that is used for combining different network resources. It breaks the bandwidth into different channels which are assigned/reassigned.

• Storage virtualization

Storage virtualization is responsible for combining various physical storage devices into a single storage device. This combination is managed from a centralized console.

• Server virtualization

Server Virtualization is the process of masking server resources. This masking includes physical servers, processors and operating systems. Resultantly the users will not need to manage complicated resources.  Resource sharing and resource utilization is also utilized.

SDDC is undoubtedly our near future. To get hands-on experience related to SDN Logic Finder can facilitate you. For that follow the link below:

https://www.logicfinder.net/wp-content/uploads/2018/06/course-2.pdf

SDN Controllers are the “brains” of the network which manage flow control below to the southbound APIs and business logic to the northbound APIs for deploying networks. A controller uses application interfaces, like OpenFlow and open virtual switch database (OVSDB).

An SDN Controller has several “pluggable” modules for performing tasks of the network. The tasks include investigating the network and performing network statistics. The functionality of the network can be increased by inserting extensions. It is done by running different algorithms and rules for orchestration.

The famous protocols used for communication with routers by SDN Controllers are OpenFlow and OVSDB. While some others are also used that are YANG or NetConf. Some more established protocols are also designed in SDN environment which includes: the Internet Engineering Task Force (IETF)– the Interface to the Routing System (i2rs) – developed  OSPF, MPLS, BGP, and IS-IS.

The whole architecture of a network gets affected by the use of protocols, For instance, OpenFlow does packet-forwarding decisions, i2rs splits the decision making for execution of distributed routing. Routing decisions are also modified by i2rs.

History (SDN Controller Platforms)

NOX was the first SDN Controller by Nicira Networks. Then in 2008, Nicira Networks gave NOX to the SDN community.

Nicira then moved to develop ONIX with NTT and Google. ONIX became the base for the VMware Controller and also Google WAN Controller. ONIX was then converted to Open Source Platform.

The earliest famous controllers were POX and Beacon. While some others were Trema, Ryu, etc.

Beacon forked Floodlight which then formed the basis of commercial Controllers of Big switch networks. The first commercial SDN Controller was Note, NEC’s ProgrammableFlow Controller.

Afterwards Cisco, HP, IBM, VMWare, Lumina Networks, and Juniper offered their SDN Controllers which were based off beacon and now on OpenDaylight available in open source and commercial versions.

OpenDaylight

OpenDaylight SDN Controller which is java based and derived from Beacon was announced On April 8, 2013. It provides support to OpenFlow and southbound APIs for providing features, like high-availability and clustering.

An OpenDaylight Controller is kept inside Java Virtual Machine (JVM) and can be deployed to several network environments. It released two codes, Hydrogen, and helium for programming the SDN controls.

The latest code of OpenDaylight is Oxygen, having a P4 and a Kubernetes plug-in for VMs.

On. Lab created the Open Networking Operating System (ONOS) for challenging OpenDaylight and companies like AT&T, Dell EMC, Intel, Google, NTT, Ciena and Juniper Networks support it.

Software-Defined Networking enables engineers, network and cloud operators to adopt a quick response to dynamic needs through a centralized control console. SDN is responsible for various latest technologies support for increasing the agility and flexibility of a network for supporting virtual servers and big infrastructures of data storage.

SDN is basically an approach. It designs and manages a network in such a way that control plane and forwarding plane which are just like brain and muscles respectively are separated. It makes the control of SDN even more programmable and SDN applications like cloud computing or mobile networks are abstracted.

SDN and SD-WAN

SDN has an extension called SD-WAN (Software-defined wide-area network). When any connection have to cover wider geographical area, SD-WAN is applied which is very helpful for the big companies. They can provide their connections to far off places widely. For example the networks of branch offices and big data centers have SD-WAN connection between them.

Nowadays, the companies are more inclined to choose SD-WAN due to its mind blowing capabilities and connecting abilities. The end-to-end encryption is also is another advantage of using SD-WAN in your company which simply means more secure networks.

Working of Software Defined Networking?

SDN Framework

Source=SDX

The architecture of Software Defined Networking is very competing in terms of centralized control which separates the control logic from computing resources. Software Defined Networking, wherever used, has some basic functional components like SDN Controller, southbound APIs and northbound APIs:

• SDN Controllers:SDN controller is referred as the brain of the whole network system. SDN Controller is responsible for providing an overall network view (centralized). It also allows a deep check of routers and switches to network admins and handle the network traffic with forwarding plane.
• Southbound APIs:The information to the switches and routers is relayed by SDN with the usage of Southbound APIs. For example OpenFlow, is a southbound API and a famous protocol of SDN.

                   OpenFlow is just a part of bigger picture and OpenFlow and SDN are not same thing.

• Northbound APIs:The other component of Software-Defined Networking is the northbound API that is used for the communication between applications and business layer. The deployment of services and programmability become much easier by using Northbound APIs.

Get detailed knowledge about SDN by clicking this link below

https://www.logicfinder.net/wp-content/uploads/2018/06/course-2.pdf

SDN architecture shows how open and software-based technologies are built by separating the control plane and data plane of the SDN.

Conventionally, both the control and data planes of SDN were integrated into the same architecture but then in 2008 OpenFlow created the SDN architecture in which both the control planes and data planes were separated and did communication by OpenFlow protocols.

Architecture

Source: SDX

In the SDN architecture, the control plane and data plane are separated by the performance of their functions and these separated functions are known as the “disaggregation,”. This is given this name because these planes have different sources rather than one integrated system. This architecture is more defined and more informative of the whole network.

The architecture of SDN has three groups according to functionality:

• SDN Applications

SDN Applications constitute a layer of programs that are used for communication of resources with the SDN. This communication is done by APIs which can be used for decision-making purposes.

These applications can also be used for managing networks or business apps. For instance, uage of application in intrusion detection or security.

• SDN Controller

The information from the application layer is passed to the logical layer of SDN controller which then further relays it to the networking components. SDN controller is engaged in extracting out the information of hardware in a network and then sends to the SDN along with all happenings and statistics.

• SDN Networking Devices

The data processing and forwarding of data path within a network is done by SDN Networking devices.

The SDN architecture has northbound and southbound APIs, used for the communication between the systems.

A Northbound API specifies the controller and applications’ connection, while the Southbound API specifies the controller and the physical networking hardware connection.

To get more knowledge about the architecture of SDN refer to the following link

https://www.logicfinder.net/wp-content/uploads/2018/06/course-2.pdf