Application Traffic Steering

September 9, 2015

by Matt Conran Blog

Application Traffic Steering

In today's digital world, where online applications play a vital role in our personal and professional lives, ensuring their seamless performance and user experience is paramount. This is where Application Traffic Steering comes into play. In this blog post, we will explore Application Traffic Steering, how it works, and its importance in optimizing application performance and user satisfaction.

Application Traffic Steering is the process of intelligently directing network traffic to different application servers or resources based on predefined rules. It efficiently distributes incoming requests to multiple servers, ensuring optimal resource utilization and responsiveness.

Application traffic steering involves intelligently directing network traffic to ensure optimal performance and resource utilization. By leveraging advanced algorithms and network intelligence, it enables efficient data transmission and improves application responsiveness.

Enhanced User Experience: By dynamically routing traffic based on application requirements and network conditions, application traffic steering minimizes latency and packet loss. This results in a seamless user experience, with faster load times and smoother interactions.

Improved Network Performance: Efficient traffic steering optimizes network resources, reducing congestion and bottlenecks. By intelligently distributing traffic across available paths, it prevents overutilization of specific links, ensuring a balanced and reliable network infrastructure.

Increased Security and Reliability: Application traffic steering can enhance security by routing traffic through secure gateways or firewalls. It also enables redundancy and failover mechanisms, ensuring continuous service availability even in the event of network disruptions.

Load Balancing: Load balancing evenly distributes network traffic across multiple servers, ensuring optimal resource utilization. It can be accomplished through various algorithms, such as round-robin, least connections, or weighted distribution.

Quality of Service (QoS): QoS techniques prioritize specific types of traffic based on predefined rules. By allocating network resources accordingly, it guarantees a certain level of performance for critical applications or services.

Content Delivery Networks (CDNs): CDNs employ application traffic steering to deliver content from geographically distributed servers. By serving content from the nearest server to the user, CDNs minimize latency and improve download speeds.

Conclusion: In the ever-evolving digital landscape, application traffic steering plays a pivotal role in optimizing user experiences, enhancing network performance, and ensuring reliability. By intelligently routing traffic and leveraging various techniques like load balancing, QoS, and CDNs, organizations can unlock the full potential of their applications while delivering seamless and efficient services.

Matt Conran

Highlights: Application Traffic Steering

SDN-based Architecture

Many protocol combinations produce an SDN-based architecture to enable application traffic steering; native OpenFlow is only one of those protocols. Some companies view OpenFlow as a core SDN design component while others don’t even include it, aka BGP SDN controller and BGP SDN. For example, the Forwarding and Control Element Separation ( ForCES) working group has spent several years working on mechanisms for separating the control and data plane.

The role of OpenFlow

They created their southbound protocol and didn’t use OpenFlow to connect the data and control planes. On the other hand, NEC was one of the first organizations to take full advantage of the OpenFlow protocol. The market’s acceptance of SDN use cases has created products that fall into an OpenFlow or non-OpenFlow bucket. The following post discusses traffic steering that outright requires OpenFlow.

The OpenFlow protocol offers additional granular control to steer traffic through an ordered list of user-specific services. A task that traditional IP destination-based forwarding struggles to do efficiently. OpenFlow offers additional flow granularity and provides topology-independent service insertion required by network overlays, such as a VXLAN.

Shortest-path routing

Every dynamic network backbone has some congested links, while others still need to be utilized. That’s because shortest-path routing protocols transmit traffic down the shortest path without regarding other network parameters, such as utilization and traffic demands. So, we need to employ application traffic engineering or traffic steering to use our network links.

Using Traffic Engineering (TE), we can redistribute packet flows to attain a more uniform distribution across all links in our network. Forcing traffic onto specific pathways lets you get the most out of your current network capacity while making it easier to deliver consistent service levels.

SD-WAN and Application-Aware Routing

Network administrators can specify service-level agreements for business-critical traffic using Application-Aware Routing.

Organizations can establish multiple connectivity paths between locations by replacing or augmenting MPLS transport circuits with Internet-as-a-Transport. By utilizing all of their bandwidth in an active/active fashion rather than continuing to invest in upgrading circuits, enterprises can realize cost savings by moving to the Internet as a means of transport while still providing the required end-user experience.

In the Application-Aware Routing process, packet loss, latency, and jitter are calculated per tunnel, then mapping network data flows to transport tunnels. A lookup in the traditional routing table is the first step in determining which tunnel should forward a specific flow. An App-Route Policy is evaluated only if multiple equal-cost matches exist in the routing table.

Before evaluating any App-Route policy, the routing table must always be considered. Depending on the routing table, the App-Route policy may select one or more paths from the list if there are multiple equal-cost routes for the destination.

The traffic will be forwarded based on the only route in the routing table, and the App-Route policy will not apply if there is only one OMP best path installed in the table and multiple equal-cost routes exist. The routing table can only be used to choose between various, equal best paths using Application-Aware Routing policies.

You may find the following helpful post for pre-information.

Application Traffic Steering. Key Traffic Steering Discussion Points:	What is traffic steering? Introduction to traffic steering and what is involved. Highlighting the different components of traffic steering and how they work. Layer 2 and Layer 3 traffic steering. Technical details on Service Insertion. Technical details on traffic tramboning and how to avoid this.

Back to basics with Traffic Engineering (TE)

The Role of Load Balancers:

Load balancing serves as the backbone of Application Traffic Steering. They act as intermediaries between clients and servers, receiving incoming requests and distributing them across multiple servers based on specific algorithms. These algorithms consider server load, response time, and availability to make informed decisions.

Multicast Traffic Steering

Multicast traffic steering is a technique used to direct data packets efficiently to multiple recipients simultaneously. It is beneficial in scenarios where a single source needs to transmit data to various destinations. Instead of sending individual copies of the data to each recipient, multicast traffic steering enables the source to transmit a single copy efficiently distributed to all interested recipients.

Lab Guide on IGMPv1

IGMPv1 is a communication protocol that enables hosts on an Internet Protocol (IP) network to join and leave multicast groups. Multicast groups allow the simultaneous transmission of data packets from a single sender to multiple recipients.

By utilizing IGMPv1, hosts can efficiently manage their participation in multicast groups and receive relevant data from senders.

Below, we have one router and two hosts. We will enable multicast routing and IGMP on the router’s Gigabit 0/1 interface.

- First, we enabled multicast routing globally; this is required for the router to process IGMP traffic.
- We enabled PIM on the interface. PIM is used for multicast routing between routers and is also required for the router to process IGMP traffic.

Benefits of Multicast Traffic Steering:

1. Bandwidth Efficiency:

Multicast traffic steering reduces network congestion and optimizes bandwidth utilization. By transmitting a single copy of the data, it minimizes the duplication of data packets, resulting in significant bandwidth savings. This is especially advantageous in scenarios where large volumes of data must simultaneously be transmitted to multiple destinations, such as video streaming or software updates.

2. Scalability:

In networks with many recipients, multicast traffic steering ensures efficient data delivery without overwhelming the network infrastructure. Instead of creating a separate unicast connection for each recipient, multicast traffic steering establishes a single multicast group, reducing the burden on the network and enabling seamless scalability.

3. Reduced Network Latency:

Multicast traffic steering reduces network latency by eliminating the need for multiple unicast connections. Data packets are delivered directly to all interested recipients, minimizing the delay caused by establishing and maintaining individual connections for each recipient. This is particularly crucial for real-time applications, such as video conferencing or live streaming, where low latency is essential for a seamless user experience.

Benefits of Application Traffic Steering:

1. Enhanced Performance: By distributing traffic across multiple servers, Application Traffic Steering reduces the load on individual servers, resulting in improved response times and reduced latency. This ensures faster and more reliable application performance.

2. Scalability: Application Traffic Steering enables horizontal scalability, allowing organizations to add or remove servers as per demand. This helps effectively handle increasing application traffic without compromising performance.

3. High Availability: By intelligently distributing traffic, Application Traffic Steering ensures high availability by rerouting requests away from servers experiencing issues or offline. This minimizes the impact of server failures and enhances overall uptime.

4. Seamless User Experience: With load balancers directing traffic to the most optimal server, users experience consistent application performance, regardless of the server they are connected to. This leads to a seamless and satisfying user experience.

Application Traffic Steering Techniques:

1. Round Robin: This algorithm distributes traffic evenly across all available servers in a cyclic manner. While it is simple and easy to implement, it does not consider server load or response times, which may result in uneven distribution and suboptimal performance.

2. Least Connections: This algorithm directs traffic to the server with the fewest active connections at a given time. It ensures optimal resource utilization by distributing traffic based on the server’s current load. However, it doesn’t consider server response times, which may lead to slower performance on heavily loaded servers.

3. Weighted Round Robin: This algorithm assigns weights to servers based on their capabilities and performance. Servers with higher weights receive a larger share of traffic, enabling organizations to prioritize specific servers over others based on their capacity.

Traditional Layer 2 and Layer 3 Service Insertion

Example: Traditional Layer 2

In a flat Layer 2 environment, everybody can reach each other by their MAC address. There is no IP routing. If you want to intercept traffic, the switch in the middle must intercept and forward to a service device, such as a firewall.

The firewall doesn’t change anything; it’s a transparent bump in the wire. You would usually insert the same service in both directions so the firewall will see both directions of the TCP session. Service insertion at Layer 2 is achieved with VLAN chaining.

For example, VLAN-1 is used on one side and VLAN-2 on the other; different VLAN numbers link areas. VLAN chaining is limited and impossible to implement for individual applications. It is also an excellent source for creating network loops. You may encounter challenges when firewalls or service nodes do not pass the Bridge Protocol Data Unit (BPDU). Be careful to use this for large-scale service insertion production environments.

Example: Layer 3 Service Insertion

Layer 3 service insertion is much safer as forwarding is based on IP headers, not Layer 2 MAC addresses. Layer 3 IP headers have a “time-to-live” field that prevents loops from looping around the network. Layer 2 frames are redirected to a transparent or inter-subnet appliance.

This means the firewall device can do a MAC header rewrite on layer 2, or if the firewall is placed in different subnets, the MAC rewrite would be automatic as you will be doing layer 3 forwardings. Layer 3 service insertion is typically implemented with Policy-Based Routing (PBR).

“User-specific services may include firewall, deep packet inspection, caching, WAN acceleration and authentication.”

Application traffic steering, service function chaining, and dynamic service insertion

Application traffic steering, service function chaining, and dynamic service insertion functionally mean the same thing. They want to insert networking functions based on endpoints or applications in the forwarding path.

Service chaining applies a specific list of ordered services (service changing) to individual traffic flows. The main challenge is the ability to steer traffic to various devices. Such devices may be physical appliances or follow the Network Function Virtualization (NFV) format.

Designing with traditional mechanisms leads to cumbersome configurations and multiple device touchpoints. For example, service appliances that need to intercept and analyze traffic could be centralized in a data center or service provider network. Service centralization results in users’ traffic “tromboning” to the central service device for interaction.

Traffic tromboning

Traffic tromboning may not be an issue for data center leaf and spine architecture with equidistant endpoints. However, other aggregated network designs that don’t follow the leaf and spine model may run into interesting problems. A central service network point also represents a “choking point” and may increase path latency. Service integration should be flexible and not designed with a “meet me” architecture.

The requirement for “flow” level granularity

Traditional routing is based on destination-based forwarding and cannot provide the granularity needed for topology-independent traffic steering. You may implement tricks with PBR and ACL, but they increase complexity and have vendor-specific configurations. Efficient traffic steering requires a granular “flow” level of interaction, which is not offered by default destination-based forwarding.

The requirement for large-scale cloud networks drives multitenancy, and network overlays are becoming the defacto technology used to meet this requirement. Network overlays require new services to be topology-independent.

Unfortunately, IP routing is limited, and different types of traffic going to the same destination cannot be distinguished. Traffic steering based on traditional Layer 2 or 3 mechanisms is inefficient and does not allow dynamic capabilities.

SDN Adoption

A single OpenFlow rule pushed down from the central SDN controller provides the same effect as complex PBR and ACL designs. Traffic steering is accomplished with OpenFlow at an IP destination or IP flow layer of granularity. This dramatically simplifies network operations as there is no need for PBR and ACL configurations. There is less network and component state as all the rules and intelligence are maintained at the SDN central controller.

A holistic viewpoint enables singular points for configuration, not numerous touchpoints throughout the network. A virtual switch can be used for the data, such as the Open vSwitch. It is a multi-layered switch that is highly well-featured.

There are alternatives for pushing ACL rules down to network devices, such as RFC 5575 and Dissemination of Flow Specification Rules. It works with a BGP control plane (BGP flow spec) that can install rules and ACL to network devices.

One significant difference between BGP flow spec and OpenFlow for traffic steering is that the OpenFlow method has a central control policy. BGP flow spec consists of several distributed devices, and configuration changes will require multiple touchpoints in the network.

Summary: Application Traffic Steering

In today’s digital age, where connectivity is paramount, efficient application traffic steering ensures optimal performance and user experience. This blog post explores the various aspects of application traffic steering and its significance in the modern landscape.

What is Application Traffic Steering?

Application traffic steering intelligently directs network traffic to different applications or services based on predetermined rules or conditions. It involves the efficient distribution of traffic to achieve load balancing, improve reliability, and enhance overall application performance.

Load Balancing for Enhanced Performance

One of the primary objectives of application traffic steering is load balancing. Efficient distribution of traffic across multiple servers or data centers prevents any single point of failure and ensures high availability. Load-balancing algorithms intelligently analyze server health, capacity, and response times to direct traffic and optimize resource utilization.

Traffic Steering Techniques

Various techniques are employed for application traffic steering. One common approach is DNS-based traffic steering, where the Domain Name System is leveraged to direct users to different IP addresses based on specific criteria. Another technique is layer 4 load balancing, which operates at the transport layer of the network stack and distributes traffic based on IP addresses and port numbers.

Content-Aware Traffic Steering

Content-aware traffic steering takes traffic steering to the next level by analyzing the actual content of the application traffic. This technique enables intelligent routing decisions based on application performance, user location, security requirements, and network conditions. It helps optimize the user experience by dynamically adapting to changing network conditions.

Application Delivery Controllers (ADCs)

ADCs are specialized devices or software solutions that are key in application traffic steering. They act as intermediaries between clients and servers, providing advanced traffic management functionalities such as load balancing, SSL offloading, caching, and security. ADCs enable organizations to efficiently manage application traffic while ensuring maximum performance, scalability, and security.

Conclusion:

In conclusion, application traffic steering is vital for optimizing application performance, enhancing user experience, and ensuring high availability. With the ever-increasing demand for seamless connectivity and robust applications, mastering application traffic steering is paramount. By leveraging various techniques and utilizing advanced tools like ADCs, organizations can confidently navigate the digital highway, delivering reliable and exceptional user experiences.

HP SDN Controller

July 20, 2015

by Matt Conran Blog

HP SDN

In today's fast-paced digital world, efficient network management is crucial for organizations to stay competitive. Traditional network infrastructures often struggle to keep up with the increasing demands of modern applications and services. Enter the HP SDN Controller, a revolutionary solution transforming how networks are managed. In this blog post, we will delve into the world of the HP SDN Controller, exploring its features, benefits, and how it is reshaping the future of network management.

The HP SDN Controller is a software-defined networking (SDN) solution designed to simplify and automate network management. By decoupling the network control plane from the underlying infrastructure, the SDN Controller empowers organizations to manage and control their networks centrally, making it easier to deploy, scale, and adapt to changing business needs.

HP SDN, short for Software-Defined Networking, is a cutting-edge approach to network architecture that separates the control plane from the data plane, allowing for more flexible and programmable network management. By decoupling these two components, HP SDN enables administrators to centrally control and manage network resources, resulting in enhanced agility, scalability, and efficiency.

HP SDN boasts a range of powerful features that set it apart from traditional networking solutions. One of its key features is the OpenFlow protocol, which enables seamless communication between the control and data planes. This facilitates dynamic network configuration, traffic engineering, and the implementation of advanced network services.

Another notable feature of HP SDN is its centralized management platform, which provides a single pane of glass for network administrators to monitor and control various network devices. This simplifies network troubleshooting, reduces the likelihood of human errors, and ensures better resource utilization.

The adoption of HP SDN brings forth a multitude of benefits for organizations across various industries. Firstly, it enhances network agility by allowing administrators to rapidly provision and configure network resources in response to changing demands. This agility enables businesses to adapt quickly to evolving market needs and stay ahead of the competition.

Secondly, HP SDN facilitates network scalability by providing a more efficient and flexible approach to network provisioning. With the ability to dynamically allocate resources, organizations can easily scale their networks to accommodate growing workloads, without the need for costly hardware upgrades.

Furthermore, HP SDN improves network security by providing granular control over network access and traffic flow. Administrators can implement robust security policies and segment their networks to isolate critical assets, mitigating the risk of unauthorized access and potential security breaches.

The real-world applications of HP SDN are vast and diverse. From data centers and campus networks to telecommunications and cloud service providers, HP SDN is revolutionizing network management across industries. Its ability to optimize network performance, improve resource utilization, and simplify network operations makes it an invaluable tool for organizations of all sizes.

In conclusion, HP SDN is a game-changing technology that empowers businesses to unlock the full potential of their network infrastructure. By providing centralized control, enhanced agility, scalability, and improved security, HP SDN paves the way for a more efficient and future-ready network ecosystem. Embracing the power of HP SDN is not just a choice; it is a strategic move towards network excellence.

Matt Conran

Highlights: HP SDN

What is SDN, and what is its role?

SDN, on the other hand, is an open architecture proposed by the Open Networking Foundation (ONF) to address current networking challenges. It facilitates configuration automation and, even better, full network programming. Compared to the conventional distributed network architecture, which bundles software and hardware into closed and vertically integrated network devices, SDN architecture elevates the level of abstraction by separating the network data plane and control plane.

By doing so, network devices become simple forwarding switches; all the control logic is centralized in software controllers, enabling the development of specialized applications and the deployment of new services.

SDN Benefits

It is believed that such aspects of SDN simplify and improve network management by allowing innovation, customizing behaviors, and controlling the network according to high-level policies expressed as centralized programs. In this way, the complexity of low-level network details is bypassed, and the fundamental architectural problems are overcome. Through SDN’s southbound interface abstraction, SDN can also easily handle the underlying infrastructure’s heterogeneity.

Application SDN

This post discusses the HP SDN Controller and its approach to HP OpenFlow based on the OpenFlow protocol. These enable an exciting approach to SDN application. Provisioning network services for an application takes too long. As a result, the network lacks agility, and making changes is still a manual process.

Usually, when an application is rolled out, you must reconfigure every device with a command CLI interface. This type of manual configuration cannot accommodate today’s application requirements. Furthermore, static rollout frameworks prohibit dynamic changes to the network, blocking the full potential that applications can bring to the business.

Remove Rigidity

Software-defined networking (SDN) aims to take rigidity out of networks and give you the visibility to make real-time changes and responses. The HP SDN Application Suite changes how the network responds to business needs by programming the network differently. The following post discusses the HP SDN controller and how it works with HP OpenFlow, where HP operates the best part of OpenFlow and uses it with traditional routing and switching. I will also provide an example of an application SDN, such as a network protector and network optimizer.

Before you proceed, you may find the following helpful post for pre-information:

SDN Controller Key HP SDN Controller Discussion Points:	Introduction to HP SDN Controller and what is involved. Highlighting HP OpenFlow and the components involved. Critical points on the SDN VAN controller. Technical details on Application SDN: Network Protector. Technical details on Application SDN: Network Optimizer

Back to basics with SDN

Software-defined networking (SDN) is the decoupling of network control from networking devices that are used to forward the traffic. The network control functionality, also known as the control plane, is decoupled from the data forwarding functionality (also known as the data plane). Furthermore, the split control is programmable by exposing several APIs. The migration of control logic, which used to be tightly integrated into networking devices into logically centralized controllers, enables the underlying networking infrastructure to be abstracted from an application’s point of view.

Key Features of HP SDN Controller:

Centralized Management: The SDN Controller provides a centralized platform for managing and configuring network devices, eliminating the need for manual configurations on individual switches or routers. This streamlined approach improves efficiency and reduces the risk of human errors.

Programmable Network: With the HP SDN Controller, network administrators can program and control the behavior of the network through open APIs. This programmability enables organizations to tailor their network infrastructure to meet specific requirements, such as optimizing performance, enhancing security, or helping new services.

Network Virtualization: Virtualizing the network infrastructure allows organizations to create multiple virtual networks on a shared physical infrastructure. The SDN Controller enables network virtualization, providing isolation and segmentation of traffic, improving network scalability, and simplifying network management.

Traffic Engineering and Performance Optimization: HP SDN Controller enables dynamic traffic engineering, allowing administrators to intelligently route traffic based on real-time conditions. This capability improves network performance, reduces congestion, and enhances user experience.

Benefits of HP SDN Controller:

Improved Network Agility: The SDN Controller enables organizations to respond quickly to changing business needs, allowing for a more agile and flexible network infrastructure. It simplifies the deployment of new applications and services, reduces time-to-market, and enhances the organization’s ability to innovate.

Enhanced Security: The SDN Controller’s centralized control and programmability allow organizations to implement security policies and access control measures more effectively. It enables granular control and visibility, empowering administrators to monitor and secure the network infrastructure against potential threats.

Cost Savings: By automating network management tasks and optimizing resource allocation, the HP SDN Controller helps organizations reduce operational costs. It eliminates the need for manual configurations on individual devices, reduces human errors, and improves overall network efficiency.

Scalability and Flexibility: The SDN Controller allows organizations to scale their network infrastructure as their business snowballs. It supports integrating new devices, services, and technologies without disrupting the existing network, ensuring flexibility and future infrastructure-proofing.

Real-World Applications of HP SDN Controller:

Data Centers: HP SDN Controller facilitates the management and orchestration of network resources in data centers, enabling organizations to allocate resources efficiently, optimize workload distribution, and enhance overall performance.

Campus Networks: By centralizing network management, the SDN Controller simplifies the configuration and deployment of services across campus networks. It allows for seamless integration of wired and wireless networks, improves scalability, and enhances user experience.

Service Providers: HP SDN Controller empowers providers to deliver agile and scalable customer services. It enables the creation of virtualized network functions and improves service provisioning, reducing time-to-market and enhancing service quality.

HP SDN

Hewlett Packard (HP) has taken a different approach to SDN. They do not want to recreate every wheel invented and roll out a blanket greenfield OpenFlow solution. Routing has worked for 40 years, so we cannot expect to see some revolutionary change to routing as it’s simply not there. Consider how complicated distributed systems are. Filing all Layer 2 and 3 protocols with OpenFlow is nearly impossible.

Layer 2 switches learn MAC addresses automatically, building a table that can selectively forward packets. So, why is there a need to replace how switches learn via Layer 2? The layer 2-learning mechanism works fine; no real driver can replace it. There are Potential drivers for Spanning Tree Protocol (STP) replacement as it is dangerous, but there is no reason to replace the layer 2-learning mechanism. So, why attempt this with OpenFlow?

HP OpenFlow

OpenFlow comes with its challenges. It derives from Stanford and is very academic. It’s hard to use and deploy in its pure form. HP adds to it and makes it more usable. They tune its implementation to match today’s network requirements using parts of OpenFlow, considering this to be HP OpenFlow and traditional routing. OpenFlow is generally not good, but certain narrow niche cases exist where it can be used. Campus networks are one of those niches, and HP is marketing its product set for this niche.

Their HP SDN controller product sets markets the network edge and leaves the core to what it does best. This allows an easy migration path by starting at the edge and moving gradually to the core ( if needed). This type of migration path keeps the potential blast radius to a minimum. An initial migration strategy that starts at the edge with SDN islands sounds appealing.

HP SDN: The SDN VAN controller

HP removed the North-South bottleneck communication. They are not sending anything to the controller. Any packets that miss an OpenFlow rule hit what is known as the last rule and are sent with standard packet processing via traditional methods.

The last rule, “Forward match all – forward normal,” reverts to the regular forwarding plane, and the network does what it’s always done. If no OpenFlow match exists, packets are forwarded via traditional means. They use a conventional distributed control plane so it can scale. Suppose you consider a controller that has to learn the topology and compute the best path through a topology.

In that case, controller-based “routing” is almost certainly more complex than distributed routing protocols. HP SDN design does not do this and combines the best from OpenFlow and Routing. OpenFlow rules take precedence over most of the control plane elements.

However, most Layer 2-control plane protocols are left to traditional methods. As a general rule, you keep time-critical things such as Link Aggregation Control Protocol (LACP) and Bidirectional Forwarding Detection (BFD) with conventional methods, and other controls that are not as time-critical can be done with OpenFlow.

HP OpenFlow: HP uses Openflow to glean and not modify the forwarding plane.

The controller can work in several modes. The first is the hybrid model, which forwards with OpenFlow rules. If all OpenFlow rules are not matched, it will fall back to standard processing. The second mode is Discovery. This is where the local SDN switches send copies of ARP and DHCP packets to the controller. By analyzing this information, the controller knows where all the hosts are and can build a network topology map. A centralized view of the network topology is a significant benefit to SDN.

They also use BBDP, which is similar to LLDP. It uses a broadcast domain and is not just link-level, enabling it to fly through OpenFlow-enabled switches. The controller does not directly influence forwarding; it scans the topology by listening to endpoint discovery information. The controller now contains a topology view, but there is no intercepting or redirecting traffic. Instead, it provides endpoint visibility across the network.

HP has started to integrate its SDN controller with Microsoft Active Directory. This gives the controller a different layer of visibility, not just IP and Subnet-based. It now gives you a higher-level language to control your network. It is making decisions based on users and groups, not subnets.

Application SDN: Network Protector

Malware and Spyware cause many issues, and the HP Protector product can help with these challenges. It enables real-time assessment and security across all SDN devices. The application SDN pushes down one rule—UDP 53 redirects to the controller. It intercepts UDP 53 and can push down ACL rules to block certain types of traffic.

They extract DNS traffic on the network’s edge and pass it to the controller. Application features rank the reputation of an external site and determine how likely you will get something nasty if you go to that site. Additional hit count capability lets the network admin track who requests what. For example, if a host requests 3000 DNS requests per second, it is considered an infected host and quarantined by sending down additional OpenFlow rules.

Application SDN and Network visualizer

An SDN application for network admins assists in troubleshooting by defining where traffic is and where it is going. The network admin can select traffic, make copies, and send it to a location. This is similar to tapping, except it is quicker and easier to roll out. Now, your network traffic is viewable on any port and switch. This app lets you go through the wire straight away.

As it is now integrated with Active Directory, when a user calls and says he has a network problem, you can extract his traffic by user ID and debug it remotely.

All you need is the User ID; in 30 seconds, you can see his packets. This is a level of visibility previously unavailable. HP gives you a level of network traffic detail incapable in the past. You could also grab ingress OSPF for analysis. This is not something you could do in the past. You can mirror LSAs and recreate the entire topology. You need access to one switch in the OSPF area.

Application SDN and Network optimizer

This application SDN is used for Microsoft LYNC and SKYPE for business. It provides automated provisioning of network policy and quality of service to endpoints. Lync and Microsoft created a diagnostic API called SDN API. This diagnostic API sends information about the calls, username, IP, and port number on both sides – ingress and egress.

It can reach the ingress switch on each side and remark the Differentiated Services Code Point (DSCP) for the ingress flows. This is how SDN applications should work. SDN implementations should be where the application requests service from the network, and the network responds. We were at Layer 4 with ACL and QoS, not the Layer 7 application. Now, with HP Network Optimizer, the application can notify the network, and the network can respond.

The HP SDN suite is about adding value to the network’s edge. Where do you allow the dynamic value of SDN to give value up to customers’ risk appetite? Keeping the dynamic SDN to the edge while keeping the core static is a significant value of SDN and an excellent migration strategy. The SDN concept takes information otherwise out of the network to the network.

Summary: HP SDN

The need for flexible and scalable networks has become paramount in today’s rapidly evolving technological landscape. Enter HP SDN (Software-Defined Networking), a revolutionary approach that transforms traditional networking by separating the control and data planes. In this blog post, we delved into the world of HP SDN, exploring its key concepts, benefits, and real-world applications.

Understanding HP SDN

HP SDN is a groundbreaking paradigm shift in networking architecture. It enables network administrators to manage and control network behavior centrally using software applications. SDN empowers organizations to build dynamic, programmable, and agile networks by decoupling the control plane from the underlying hardware.

Key Components of HP SDN

To comprehend the workings of HP SDN, it is essential to grasp its key components. The SDN Controller acts as the brain of the network, orchestrating and directing network traffic. It communicates with SDN switches that forward packets based on the instructions received from the controller. OpenFlow, a vital protocol, facilitates communication between the controller and switches, ensuring seamless interoperability.

Benefits of HP SDN

The benefits of HP SDN are manifold. Firstly, it offers enhanced network agility, allowing administrators to adapt to changing business requirements swiftly. Secondly, SDN simplifies network management, reducing operational complexities. Moreover, by centralizing control, SDN enables intelligent traffic engineering, improving network performance and efficiency. Lastly, HP SDN promotes innovation and accelerates the deployment of new services, driving business growth.

Real-World Applications

HP SDN has found its applications across various industries. SDN enables dynamic resource allocation in data centers, optimizes workload distribution, and improves overall efficiency. SDN facilitates secure and scalable network connectivity for students and faculty in the education sector. Furthermore, SDN plays a crucial role in service provider networks, enabling the rapid provisioning of new services and enhancing service quality.

Conclusion:

In conclusion, HP SDN represents a paradigm shift in networking, revolutionizing how we design, manage, and operate networks. Its ability to centralize control, enhance agility, and drive innovation makes it a game-changer in the industry. As organizations strive for flexible and scalable networks, HP SDN emerges as a powerful solution that paves the way for future networks.

Hyperscale Networking

May 20, 2015

by Matt Conran Blog

Hyperscale networking

In today's digital age, where data is generated at an unprecedented rate, traditional networking infrastructures are struggling to keep up with the demand. Enter hyperscale networking, a revolutionary paradigm transforming how we build and manage networks. In this blog post, we will explore the concept of hyperscale networking, its benefits, and its impact on various industries.

Hyperscale networking refers to quickly and seamlessly scaling network infrastructure to accommodate massive amounts of data, traffic, and users. It is a distributed architecture that leverages cloud-based technologies and software-defined networking (SDN) principles to achieve unprecedented scalability, agility, and efficiency.

Hyperscale networking is a revolutionary approach to networking that enables organizations to scale their networks rapidly and efficiently. Unlike traditional networking architectures, hyperscale networking is designed to handle massive amounts of data and traffic with ease. It leverages advanced technologies and software-defined principles to create flexible, agile, and highly scalable networks.

One of the key benefits of hyperscale networking is its ability to handle exponential data growth. With the rise of cloud computing, big data, and the Internet of Things (IoT), businesses are generating and processing enormous volumes of data. Hyperscale networking allows organizations to scale their networks seamlessly to accommodate this data explosion.

Another advantage of hyperscale networking is its cost-effectiveness. By leveraging commodity hardware and open-source software, organizations can build and manage their networks at a fraction of the cost compared to traditional networking solutions. This scalability and cost-efficiency make hyperscale networking an attractive option for businesses of all sizes.

Hyperscale networking has had a profound impact on modern businesses across various industries. It has enabled cloud providers to deliver scalable and reliable services to millions of users worldwide. Additionally, hyperscale networking has empowered enterprises to embrace digital transformation initiatives by providing the infrastructure needed to support modern applications and workloads.

Moreover, hyperscale networking has played a crucial role in enabling the deployment of emerging technologies such as artificial intelligence (AI), machine learning (ML), and edge computing. These technologies heavily rely on robust and flexible networking architectures to deliver real-time insights and drive innovation.

In conclusion, hyperscale networking is a game-changer in the world of networking. Its ability to handle massive data volumes, cost-effectiveness, and impact on modern businesses make it a compelling choice for organizations looking to scale their networks and embrace digital transformation. As the demand for data continues to grow, hyperscale networking will undoubtedly play a pivotal role in shaping the future of connectivity.

Matt Conran

Highlights: Hyperscale networking

SDN data plane

It consists of a distributed set of forwarding network elements (mainly switches) responsible for forwarding packets. SDN uses software-based control through an open, vendor-neutral southbound interface, and the control plane and data plane are separated.

Several well-known candidate protocols for the southbound interface exist, including OpenFlow (McKeown et al. 2008; Costa et al. 2021) and ForCES (Forwarding and Control Element Separation). In both cases, the control and forwarding planes are divided into network elements, and the communication between them is standardized. In terms of network architecture design, these solutions differ in many ways.

SDN control plane

In SDN architectures, the control plane is the backbone that communicates between network applications and devices through a centralized software controller. The SDN controllers deliver relevant information to SDN applications by translating applications’ requirements into underlying elements of the data plane.

In SDN, the control layer called the network operating system (NOS), abstracts network data from the application layer. Policies can be specified while implementation details are hidden.

Typically, the control plane is logically centralized yet implemented as a physically distributed system for scalability and reliability. East-west APIs are needed to enable communication and network information exchange across SDN controllers.

SDN application plane

An SDN application plane consists of control programs that implement logic and strategies for network control. An open northbound API connects this higher-level plane to the control plane. The SDN controller translates the network requirements of SDN applications into southbound-specific commands and forwarding rules that dictate how the SDN devices should behave. SDN applications that run on top of existing controller platforms include routing, traffic engineering (TE), firewalls, and load balancing.

Example: Big Switch

Throughout the last 5-years, data center innovation has come from companies such as Google, Facebook, Amazon, and Microsoft. These companies are referred to as hyper-scale players. The vision of Big Switch is to take hyperscale concepts developed by these companies and bring them to smaller data centers around the world in the version of hyperscale networking, enabling a hyperscale architecture.

Before you proceed, you may find the following helpful post for pre-information:

Hyperscale Networking Key Hyperscale Architecture Discussion Points:	Introduction to hyperscale architecture and what is involved. Highlighting the challenges of a standard chassis design. Critical points on bare metal switches. Technical details on the core and pod designs. SDN controller architecture and distributed routing.

Back to basic with OpenFlow

With OpenFlow, the switching device has no control plane, as the controller interacts directly with the FIB. Instead, OpenFlow provides a packet format and protocol to carry these packets that now describes forwarding table entries in the FIB. In OpenFlow documentation, the FIB is referred to as the flow table, which contains information about each flow the switch needs to know about.

Critical Benefits of Hyperscale Networking:

1. Scalability: Hyperscale networking allows organizations to scale their networks effortlessly as demand grows. With traditional networking, scaling often involves costly hardware upgrades and complex configurations. In contrast, hyperscale networks can scale horizontally by adding more commodity hardware, resulting in significantly lower costs and simplified network management.

2. Agility: In the fast-paced digital landscape, businesses must adapt quickly to changing requirements. Hyperscale networking enables organizations to deploy and provision network resources on demand, reducing time-to-market for new services and applications. This agility empowers businesses to respond rapidly to customer demands and gain a competitive edge.

3. Enhanced Performance: Hyperscale networks are designed to handle massive data and traffic efficiently. By distributing workloads across multiple nodes, these networks can deliver superior performance, low latency, and high throughput. This translates into a seamless user experience and improved productivity for businesses.

4. Cost Efficiency: Traditional networking often involves significant upfront investments in proprietary hardware and complex infrastructure—hyperscale networking leverages off-the-shelf hardware and cloud-based technologies, resulting in cost savings and reduced operational expenses. Moreover, the ability to scale horizontally eliminates the need for expensive equipment upgrades.

Hyperscale Networking in Various Industries:

1. Cloud Computing: Hyperscale networking is the backbone of cloud computing platforms. It enables cloud service providers to deliver scalable and reliable services to millions of users worldwide. By leveraging hyperscale architectures, these providers can efficiently manage massive workloads and deliver high-performance cloud services.

2. Internet of Things (IoT): The proliferation of IoT devices generates enormous amounts of data that must be processed and analyzed in real-time. Hyperscale networking provides the infrastructure to handle the massive data influx from IoT devices, ensuring seamless connectivity, efficient data processing, and rapid insights.

3. E-commerce: The e-commerce industry heavily relies on hyperscale networking to handle the ever-increasing number of online transactions, user interactions, and inventory management. With hyperscale networks, e-commerce platforms can ensure fast and secure transactions, reliable inventory management, and personalized user experiences.

Hyperscale Architecture

Hyperscale networking consists of three elements. The first is bare metal and open switch hardware. Bare metal switches are sold without software and makeup 10% of all ports shipped. The second hyperscale aspect is Software-Defined Networking (SDN). In SDN vision, one device acts as a controller, managing the physical and virtual infrastructure.

The third element is the actual data architecture—Big Switch leverages what’s known as the Core-and-Pod design. Core-and-Pod differs from the traditional core, aggregation, and edge model, allowing incredible scale and automation when deploying applications.

Standard Chassis Design vs. SDN Design

Standard chassis-based switches have supervisors, line cards, and fabric backplanes. In addition, a proprietary protocol runs between the blades for controls. Big Switch has all of these components but is named differently. Under the covers, the supervisor module acts like an SDN controller, programming the line cards and fabric backplane.

Instead of supervisors, they have a controller, and the internal chassis proprietary protocol is OpenFlow. The leaf switches are treated like line cards, and the spine switches are like the fabric backplane. In addition, they offer an OpenFlow-integrated architecture.

Traditional data center topologies operate on hierarchical tree architecture. The big switch follows a new networking architecture called spine leaf architecture, which overcomes the shortcomings of conventional tree architectures. To map the leaf and spine to traditional data center terminology, the leaf is accessed, and the spine is a core switch.

In addition, the leaf and spine operate on the concept that every leaf has equidistant endpoints. Designs with equidistant endpoints make POD placement and service insertion easier than hierarchical tree architecture.

Big Switch hyperscale architecture has multiple connection points. Similar to Equal Cost Multipath (ECMP) fabric and Multi-Chassis Link Aggregation (MLAG), enabling layer 2 and layer 3 multipathing. This type of connectivity allows you to have network partition problems without having a global effect. You still lose your spin switch’s capacity but have not lost connectivity. The controller controls all this and has a central view.

Losing a leaf switch in a leaf and spine architecture is not a big deal as long as you have configured multiple paths.

Bare metal switches

The first hyperscale design principle utilizes bare metal switches. Bare metal switches are Ethernet switches sold without software. Disaggregating the hardware from the switch software allows you to build your switch software stack. It is cheaper in terms of CAPEX and will enable you to tune the operating system to your needs better. It gives you the ability to tailor the operations to specific requirements.

Core and pod design

Traditional core-agg-edge is a monolithic design that cannot evolve. Hyperscale companies are now designing to a core-and-pod design, allowing operations to improve faster. Data centers are usually made up of two core components. One is the core with the Layer 3 routes for ingress and egress routing. Then, you have a POD, a self-contained unit connected to the core.

Intra-communication between PODs is done via the core. A POD is a certified design of servers, storage, and network grouped into standard services. Each POD contains an atomic networking, computing, and storage unit attached directly to the core via Layer 2 or 3. Due to a PODs-fixed configuration, automation is simple and stable.

Hyperscale Networking and Big Switch Products

Big Tap and Big Cloud Fabric are two product streams from Big Switch. Both use a fabric architecture built on white box switches with a centralized controller and POD design. Big Clouds’ hyperscale architecture is designed as a network for a POD.

Each Big Cloud architecture instance is a pair of redundant SDN controllers, and a leaf/spine topology is the network for your POD. Switches have zero-touch, so they are stateless. Turn them on, and they boot and download the switch image and configuration. It auto-discovers all of the links and troubleshoots any physical problems.

SDN controller architecture

There are generic architectural challenges of SDN controller-based networks. The first crucial question is, where are the controller and network devices split? In OpenFlow, it’s clear that the split is between the control plane and the data plane. The split affects the outcomes from various events, such as a controller bug, controller failure, network partitions, and the size of the failure domain.

You might have an SDN controller cluster, but every single controller is still a single point of failure. The controller cluster protects you from hardware failures but not from software failures. If someone misconfigures or corrupts the controller database, you lose the controller regardless of how many controllers are in a cluster.

Every controller is a single fat fingers domain. Due to the complexity of clusters and clustering protocols, you could implement failures by the lousy design. Every distributed system is complex, and it is even more challenging if it has to work with real-time data.

SDN controller – Availability Zones

The optimum design is to build controllers per availability zone. If one controller fails, you lose that side of the fabric but still have another fabric. To use this concept, you must have applications that can run in multiple availability zones. Availability zones are great, but applications must be adequately designed to use them. Availability zones usually relate to a single failure domain.

How do you deal with failures, and what failure rate is acceptable? The failure rate acceptance level drives the redundancy in your network. Full redundancy is a great design goal as it reduces the probability of total network failure. But full redundancy will never give you 100% availability. Network partitions still happen with fully redundant networks.

Be careful of split-brain scenarios, where one controller looks after one partition and another looks after the other partitions. Big Switch overcomes time with a distributed control plane. The forwarding elements are aligned so a network partition can happen.

Hyperscale Architecture: Big Switch distributed routing.

For routing, they have the concept known as a tenant router. With the tenant router, you can say that these two broadcast domains can talk to each other via policy points. A tenant router is a logical router physically distributed throughout the entire network. Every switch has a copy of the tenant router’s routing table that is local to it. The routing state is spread everywhere. Traffic needs to cross no specific layer 3 points to get from one layer 2 segment to the other.

As all the leaf switches have a distributed copy of the database, all routing takes the most optimal path. When two broadcast domains are on the same leaf switch, traffic does not have to hairpin to a physical layer 3 points.

You can map the application directly to the tenant router, which acts like a VRF with VRF packet forwarding hardware. This is known as micro-segmentation. With this, you can put a set of applications or VMs in a tenant, demarcate the network by the tenant, and have a per-tenant policy.

Hyperscale networking revolutionizes how we build and manage networks in the digital era. Its ability to scale effortlessly, provide agility, enhance performance, and reduce costs makes it a game-changer in various industries. As data volumes grow, organizations must embrace hyperscale networking to stay competitive, deliver exceptional user experiences, and drive innovation in a rapidly evolving digital landscape.

Summary: Hyperscale networking

In today’s digital age, where data is generated at an unprecedented rate, the need for efficient and scalable networking solutions has become paramount. This is where hyperscale networking steps in, offering a revolutionary approach to connectivity. In this blog post, we delved into the world of hyperscale networking, exploring its key features, benefits, and impact on the ever-evolving landscape of technology.

Understanding Hyperscale Networking

Hyperscale networking refers to the ability to scale network infrastructure dynamically and rapidly to meet the demands of large-scale applications and services. It involves using robust hardware and software solutions to handle massive amounts of data and traffic without compromising performance or reliability. By leveraging high-speed interconnections, virtualization technologies, and advanced routing algorithms, hyperscale networks provide a solid foundation for modern digital ecosystems.

Key Features and Benefits

One of the defining features of hyperscale networking is its ability to scale horizontally, allowing organizations to expand their network infrastructure seamlessly. With hyperscale architectures, businesses can easily add or remove resources as needed, ensuring optimal performance and cost-efficiency. Additionally, hyperscale networks offer improved resiliency and fault tolerance through redundant components and automated failover mechanisms. This ensures minimal downtime and uninterrupted service delivery, which is critical for mission-critical applications.

The Impact on Cloud Computing

Hyperscale networking has had a profound impact on the world of cloud computing. With hyperscale networks, cloud service providers can deliver scalable and elastic infrastructure to their customers, enabling them to provision resources based on demand rapidly. This scalability and flexibility have transformed how businesses operate, allowing them to focus on innovation and growth without worrying about infrastructure limitations. Furthermore, hyperscale networking has paved the way for the rise of edge computing, bringing computing resources closer to end users and reducing latency.

Challenges and Considerations

While hyperscale networking offers numerous advantages, it is not without its challenges. Managing and securing vast amounts of data flowing through hyperscale networks requires robust monitoring and security measures. Organizations must also consider the cost implications of scaling their network infrastructure, as hyperscale solutions can be resource-intensive. Moreover, ensuring compatibility and seamless integration with existing systems and applications can pose challenges during the transition to hyperscale networking.

Conclusion:

Hyperscale networking is revolutionizing the way we connect, scale, and operate in the digital world. Its ability to seamlessly scale, improve resiliency, and drive innovation has made it a game-changer for businesses across various industries. As technology continues to advance and data demands grow, hyperscale networking will play an increasingly vital role in enabling the next generation of digital transformation.

SDN Data Center

August 9, 2014

by Matt Conran Blog

SDN Data Center

The world of technology consists of data centers that play a crucial role in storing and managing vast amounts of information. Traditional data centers, however, have faced challenges in terms of scalability, flexibility, and efficiency. Enter Software-Defined Networking (SDN), a groundbreaking approach reshaping the landscape of data centers. In this blog post, we will explore the concept of SDN, its benefits, and its potential to revolutionize data centers as we know them.

In SDN, the functions of network nodes (switches, routers, bare metal servers, etc.) are abstracted so they can be managed globally and coherently. A single controller, the SDN controller, manages the whole entity coherently by detaching the network device's decision-making part (control plane) from its operational part (data plane).

The name "Software Defined" comes from this controller, allowing "network programmability." The Open Networking Foundation (ONF) was founded in March 2011 to promote the concept and development of OpenFlow. In 2009, the University of Stanford (US) and its research center (ONRC) published the first OpenFlow specifications, one of the protocols used by SDN controllers.

- Traditional data center networks often face challenges such as complex configurations, limited scalability, and lack of agility. SDN technology addresses these issues by introducing a software-based approach to network management. With SDN, data center operators can automate network provisioning, streamline operations, and achieve greater scalability. Moreover, SDN enables network virtualization, allowing multiple virtual networks to coexist on a shared physical infrastructure, leading to improved resource utilization.

- Security is a top priority for data centers, and SDN brings notable advancements in this domain. With its centralized control, SDN provides a holistic view of the network, enabling enhanced security policies and threat detection mechanisms. By dynamically allocating resources and isolating traffic, SDN mitigates potential security breaches. Additionally, SDN facilitates network resilience through features like automatic traffic rerouting, load balancing, and real-time network monitoring.

- The applications of SDN in data centers are vast and varied. One notable use case is network virtualization, which allows data center operators to create isolated virtual networks for different tenants or applications. This enhances resource allocation and provides better network performance. SDN also enables efficient load balancing across servers, optimizing resource utilization and improving application delivery. Furthermore, SDN facilitates the deployment of network services, such as firewalls and intrusion detection systems, in a more agile and scalable manner.

Matt Conran

Highlights: SDN Data Center

What is SDN

With SDN, network nodes (switches, routers, bare-metal servers, etc.) are abstracted from their functions, which allows them to be managed globally and coherently. An SDN controller coherently manages the entire system through its control plane (control plane) and data plane (data plane (data plane). “Network programmability” is enabled by Software Defined Controllers. March 2011 saw the founding of the Open Networking Foundation (ONF), a non-profit organization dedicated to promoting and developing OpenFlow. Research centers, such as Stanford University’s ONRC, which produced the first OpenFlow specifications in 2009, were interested in using OpenFlow as a protocol for SDN controllers.

Why do we need it?

IT teams are responsible for building and managing IT infrastructure and applications, but they should also serve key business drivers for their organization, such as these:

Affordability
Growth
Adaptability
Ability to scale
A secure environment.

As we know, non-SDN networks in the data center space have many drawbacks and present many operational challenges to modern IT infrastructures. In addition to these challenges, organizations from diverse industries raised new demands for SDN.

SDN Data Centers

In addition to OpenFlow, software-defined networks (SDNs) provide another paradigm shift. In the last few years, the idea of separating the data plane, which runs in hardware ASICs on network switches, from the control plane, which runs on a central controller, has gained traction. This effort aims to develop standardized OpenFlow APIs that expose rich functionality from the hardware to the controller. For the entire data center cluster comprised of different types of switches to be uniformly programmed to enforce a specific policy, SDNs should promote programmatic interfaces that switch vendors should support. At its simplest, the data plane merely programs hardware based on the controller’s directions by serving as a set of “dumb” devices.

Scalability

As server ports increased in density, data centers grew, making it impossible to keep up. A limited number of MAC addresses, inactive links, and multicast streams prevented multicast streams from being transported in this case. Infrastructure growth became more than a “nice to have” as needs evolved. Using SDN controllers and standardized off-the-shelf switches, adding new switches and configuring their configurations quickly became easy.

To maximize downlink throughput, all links on switches must be utilized. Local networks already know about the widespread use of spreading trees (which disable parts of links). As a result of the phenomenal growth of server density, various multipathing scenarios have been addressed using things like Multi-Chassis EtherChannel (MEC) and ECMP (Equal Cost Multi-Path) with CLOS architectures.

Virtualization is one of the abstraction capabilities brought by SDN. Multiple isolated virtual networks were used to compute and store data on servers. There was also a virtualization movement in the network industry. At different layers, SDN has been developed in several variants.

ClOS-based architectures

In recent years, high-speed network switches have made CLOS-based31 architectures extremely popular. The CLOS topology has a simple rule: switches at tier x should only be connected to switches at tier x-1 and x+1 and never to other switches at the same tier. In this topology, redundancy provides high resilience, fault tolerance, and traffic load sharing. Due to the many redundant paths between any two switches, network resources can be utilized efficiently. There is no oversubscription in CLOS-based architectures, which may be advantageous for some applications due to the huge bisection bandwidth. Additionally, the relatively simple topology alleviates the burden of having separate core and aggregation layers inherent in traditional three-tier architectures, which help troubleshoot traffic.

What problems do we have, and what are we doing about them? Ask yourself: Are data centers ready and available for today’s applications and tomorrow’s emerging data center applications? Businesses and applications are putting pressure on networks to change, ushering in a new era of data center design. From 1960 to 1985, we started with mainframes and supported a customer base of about one million users.

Example: ACI Cisco

ACI Cisco, short for Application Centric Infrastructure, is a software-defined networking (SDN) solution developed by Cisco Systems. It provides a holistic approach to managing and automating network infrastructure, allowing organizations to achieve agility, scalability, and security all in one framework.

Cisco ACI is a software-defined networking (SDN) solution that brings automation, scalability, and agility to network infrastructure. It combines physical and virtual elements, creating a unified and programmable network fabric that simplifies operations and accelerates application deployment. By abstracting network policies from the underlying infrastructure, Cisco ACI enables organizations to achieve policy-driven automation and policy-based security across the entire network.

Scalability and Agility:

With the increasing demands of modern business applications, scalability and agility are paramount. Cisco ACI offers a highly scalable architecture that can adapt to changing network requirements. By leveraging a spine-leaf topology and VXLAN overlays, Cisco ACI provides a flexible and scalable foundation that can seamlessly grow to accommodate evolving business needs.

Example: Software-defined data centers

To offer computing and network services to many clients, software-defined data centers (SDDCs) use virtualization technologies to separate hardware infrastructure into virtual machines. All computing, storage, and networking resources can be abstracted and represented as software in a virtualized data center. Anybody could access the data center resources if sold as a service.

Software-defined networking (SDN) and virtual machines are components of SDDCs. Many other open and proprietary software platforms exist for virtualizing computing resources besides Citrix, KVM, OpenDaylight, OpenStack, OpenFlow, Red Hat, and VMware.

The advantage of SDDC is that clients do not have to build their infrastructure. They can meet their computing, networking, and storage needs by renting resources from the cloud. It is advantageous for software companies or service providers to have centralized data centers because they can serve many clients simultaneously. Hardware and storage costs are plummeting, a significant factor driving SDDC and cloud computing. Infrastructure as a Service (IaaS) becomes more economical as these resources become cheaper, making it more advantageous to build large data centers on a large scale.

Example: Open Networking Foundation

We also have the Open Networking Foundation ( ONF ), which leverages SDN principles, employs open-source platforms, and defines standards to build and operate open networking. The ONF’s portfolio includes several areas, such as mobile, broadband, and data centers running on white box hardware.

Related: Before you proceed, you may find the following post helpful:

Data Center Applications Key SDN Data Center Design Discussion Points:	Introduction to the SDN Data Center and what is involved. Highlighting the details of the different types of traffic patterns. Technical details on the issues with spanning tree protocol. Scenario: Building a scalable data center. Details on VXLAN and the use of overlay networking.

The Future of Data Centers

Exploring Software-Defined Networking (SDN)

In recent years, the rapid advancement of technology has given rise to various innovative solutions transforming how data centers operate. One such revolutionary technology is Software-Defined Networking (SDN), which has garnered significant attention and is set to reshape the landscape of data centers as we know them. In this blog post, we will delve into the fundamentals of SDN and explore its potential to revolutionize data center architecture.

SDN is a networking paradigm that separates the control plane from the data plane, enabling centralized control and programmability of network infrastructure. Unlike traditional network architectures, where network devices make independent decisions, SDN offers a centralized management approach, providing administrators with a holistic view and control over the entire network.

1st Lab Guide: Cisco ACI

The following screenshots show the topology of the Cisco ACI. The design follows the layout of a leaf and spine architecture. The leaf switches connect to the spines and not to each other. All workloads and even WAN networks connect to the leaf layer.

The ACI goes through what is known as Fabric Discovery, where much of this is automated for you, borrowing the main principle of an SDN data center of automation. As you can see below, the fabric has been successfully discovered. There are three registered nodes – Spine, Leaf-a, and Leaf-b. The ACI is based on the Cisco Nexus 9000 Series.

The Benefits of SDN in Data Centers

Enhanced Network Flexibility and Scalability:

SDN allows data center administrators to allocate network resources dynamically based on real-time demands. With SDN, scaling up or down becomes seamless, resulting in improved flexibility and agility. This capability is crucial in today’s data-driven environment, where rapid scalability is essential to meet growing business demands.

Simplified Network Management:

SDN abstracts the complexity of network management by centralizing control and offering a unified view of the network. This simplification enables more efficient troubleshooting, faster service provisioning, and streamlined network management, ultimately reducing operational costs and increasing overall efficiency.

Increased Network Security:

By offering a centralized control plane, SDN enables administrators to implement stringent security policies consistently across the entire data center network. SDN’s programmability allows for dynamic security measures, such as traffic isolation and malware detection, making it easier to respond to emerging threats.

SDN and Network Virtualization:

SDN and network virtualization are closely intertwined, as SDN provides the foundation for implementing network virtualization in data centers. By decoupling network services from physical infrastructure, virtualization enables the creation of virtual networks that can be customized and provisioned on demand. SDN’s programmability further enhances network virtualization by allowing the rapid deployment and management of virtual networks.

Back to Basics: SDN Data Center

From 1985 to 2009, we moved to the personal computer, client/server model, and LAN /Internet model, supporting a customer base of hundreds of millions. From 2009 to 2020+, the industry has completely changed. We have various platforms (mobile, social, big data, and cloud) with billions of users, and it is estimated that the new IT industry will be worth 4.8T. All of these are forcing us to examine the existing data center topology.

SDN data center architecture is a type of architectural model that adds a level of abstraction to the functions of network nodes. These nodes may include switches, routers, bare metal servers, etc.), to manage them globally and coherently. So, with an SDN topology, we have a central place to work a disparate network of various devices and device types.

We will discuss the SDN topology in more detail shortly. At its core, SDN enables the entire network to be centrally controlled, or ‘programmed,’ using a software SDN application layer. The significant advantage of SDN is that it allows operators to manage the whole network consistently, regardless of the underlying network technology.

Statistics don’t lie.

The customer has changed and is making us change our data center topology. Content doubles over the next two years, and emerging markets may overtake mature markets. We expect 5,200 GB of data/per person created in 2020. These new demands and trends are putting a lot of duress on the amount of content that will be made, and how we serve and control this content poses new challenges to data networks.

Knowledge check for other software-defined data center market

The software-defined data center market is considerable. In terms of revenue, it was estimated at $43.178 billion in 2020. However, this has grown significantly; now, the software-defined data center market will grow to $120.3 billion by 2025, representing a CAGR of 22.4%.

Knowledge Check for SDN data center architecture and SDN Topology

Software Defined Networking (SDN) simplifies computer network management and operation. It is an approach to network management and architecture that enables administrators to manage network services centrally using software-defined policies. In addition, the SDN data center architecture enables greater visibility and control over the network by separating the control plane from the data plane. Administrators can control routing, traffic management, and security by centralized managing networks. With global visibility, administrators can control the entire network. They can then quickly apply network policies to all devices by creating and managing them efficiently.

The Value: SDN Topology

An SDN topology separates the control plane from the data plane connected to the physical network devices. This allows for better network management and configuration flexibility, and configuring the control plane can create a more efficient and scalable network.

The SDN topology has three layers: the control plane, the data plane, and the physical network. The control plane controls the data plane, which carries the data packets. It is also responsible for setting up virtual networks, configuring network devices, and managing the overall SDN topology.

A personal network impact assessment report

I recently approved a network impact assessment for various data center network topologies. One of my customers was looking at rate-limiting current data transfer over the WAN ( Wide Area Network ) at 9.5mbps over 10 hours for 34GB of data transfer at an off-prime time window. Due to application and service changes, this particular customer plans to triple that volume over the next 12 months.

They result in a WAN upgrade and a change in the scope of DR ( Disaster Recovery ). Big Data, Applications, Social Media, and Mobility force architects to rethink how they engineer networks. We should concentrate more on scale, agility, analytics, and management.

SDN Data Center Architecture: The 80/20 traffic rule

The data center design was based on the 80/20 traffic pattern rule with Spanning Tree Protocol ( 802.1D ), where we have a root, and all bridges build a loop-free path to that root. This results in half ports forwarding and half in a blocking state—completely wasting your bandwidth even though we can load balance based on a certain number of VLANs forwarding on one uplink and another set of VLANs forwarding on the secondary uplink.

We still face the problems and scalability of having large Layer 2 domains in your data center design. Spanning tree is not a routing protocol; it’s a loop prevention protocol, and as it has many disastrous consequences, it should be limited to small data center segments.

SDN Data Center	Data Center Stability
Layer 2 to the Core layer
STP blocks reduandant links
Manual pruning of VLANs for redudancy design
Rely on STP convergence for topology changes
Efficient and stable design

Data Center Topology: The Shifting Traffic Patterns

The traffic patterns have shifted, and the architecture needs to adapt. Before, we focused on 80% leaving the DC, while now, a lot of traffic is going east to west and staying within the DC. The original traffic pattern made us design a typical data center style with access, core, and distribution based on Layer 2, leading to Layer 3 transport. The route you can approach was adopted as Layer 3, which adds stability to Layer 2 by controlling broadcast and flooding domains.

The most popular data architecture in deployment today is based on very different requirements, and the business is looking for large Layer 2 domains to support functions such as VMotion. We need to meet the challenge of future data center applications, and as new apps come out with unique requirements, it isnt easy to make adequate changes to the network due to the protocol stack used. One way to overcome this is with overlay networking and VXLAN.

Overlay networking — Diagram: Overlay Networking with VXLAN

The Issues with Spanning Tree

The problem is that we rely on the spanning tree, which was useful before but is past its date. The original author of the spanning tree is now the author of THRILL ( replacement to STP ). STP ( Spanning Tree Protocol ) was never a routing protocol to determine the best path; it was used to provide a loop-free path. STP is also a fail-open protocol ( as opposed to a Layer 3 protocol that fails closed ).

One of the spanning trees’ most significant weaknesses is their failure to open. If I don’t receive a BPDU ( Bridge Protocol Data Unit ), I assume I am not connected to a switch and start forwarding on that port. Combining a fail-open paradigm with a flooding paradigm can be disastrous.

Lab Guide: STP va Routing Blocking Links

Next, let’s address the Spanning Tree Protocol on a network of 3 switches. STP is there to help, but in some cases, it blocks specific ports based on the default configuration or by the administrator forcing traffic to get a certain way. Either way, you can lose bandwidth. It is easy to demonstrate this by looking at three switches in the diagram. You would want all of these links in a forwarding state, but with STP, one of the links is blocked to prevent loops.

Since the spanning tree is enabled, all our switches will send a unique frame to each other called a BPDU (Bridge Protocol Data Unit). The spanning tree requires two pieces of information in this BPDU: the MAC address and Priority. Together, the MAC address and priority make up the bridge ID.

The spanning tree requires the bridge ID for its calculation. Let me explain how it works:

First, a spanning tree will elect a root bridge; this root bridge will have the best “bridge ID.”
The switch with the lowest bridge ID is the best one.
The priority is 32768 by default, but we can change this value.

So, who will become the root bridge? In our example, SW1 will become the root bridge! The bridge ID is made up of priority and MAC address. Since all switches have the same priority, the MAC address will be the tiebreaker. SW1 has the lowest MAC address, thus the best bridge ID, and will become the root bridge. The ports on our root bridge are always designated, which means they are forwarding.

Above, you see that SW1 has been elected as the root bridge, and the “D” on the interfaces stands for designated.

Now we have agreed on the root bridge, our next step for all our “non-root” bridges (so that’s every switch that is not the root) will be to find the shortest path to our root bridge! The shortest path to the root bridge is called the “root port.” Take a look at my example:

Port States:

If you have played with some Cisco switches before, you might have noticed that every time you plugged in a cable, the LED above the interface was orange and, after a while, became green. What is happening at this moment is that the spanning tree is determining the state of the interface; this is what happens as soon as you plug in a cable:

The port is in listening mode for 15 seconds. In this phase, it will receive and send BPDUs but not learn MAC addresses or transmit data.
The port is in learning mode for 15 seconds. We are still sending and receiving BPDUs, but now the switch will also learn MAC addresses. There is still no data transmission, though.
Now we go into forwarding mode, and finally, we can transmit data!

So, how does this compare to routing? With layer 3, we have a TTL, meaning we can stop loops as long as there is no complicated route redistribution at different points in the network topology. So, let’s look at the following example, which uses RIP.

RIP is a distance vector routing protocol and the simplest one. We’ll start by paying attention to the distance vector class. What does the name distance vector mean?

- Distance: How far away? In the routing world, we use metrics.
- Vector: Which direction? In the routing world, we care about which interface and the next router’s IP address to send the packet to.

Notice below we are not blocking ports. Instead, we are load balancing.

Analysis:

Load-sharing between packets or destinations (actually source/destination IP address pairs) is supported by Cisco Express Forwarding (CEF) without performance degradation (without CEF, per-packet load-sharing requires process switching). Even though there is no performance impact on the router, per-packet load sharing almost always results in out-of-order packets. As a result of packet reordering, TCP throughput might be reduced in high-speed environments (per-packet load-sharing improves per-flow throughput in low-speed/few-flow scenarios) or applications that cannot survive out-of-order packet delivery, for example, Fast Sequenced Transport for SNA over IP or voice/video streams, may suffer.

Use the ip load-sharing per-packet interface configuration command to configure per-packet load-sharing (the default is per destination). This command must be used to configure all outgoing interfaces where traffic is load-shared.

STP has a bad reputation

STP, in theory, prevents bridging loops. Many reasons contribute to STP’s lousy reputation in practice.

If you prefer plug-and-pray networking over proper routing protocols, you must accept that design choice. There is little we can do in this situation. To use alternate paths, you need an appropriate routing protocol, regardless of whether you’re routing on layer 2 (TRILL, SPB) or layer 3 (IP). Forward-on behavior is one of the main problems with STP. All links forward traffic until BPDUs block some of them.

A forwarding loop is almost certain to occur if a device drops BPDUs or if a switch loses its control plane (for example, due to a memory leak).

Design a Scalable Data Center Topology

To overcome the limitation, some are now trying to route ( Layer 3 ) the entire way to the access layer, which has its problems, too, as some applications require L2 to function, e.g., clustering and stateful devices—however, people still like Layer 3 as we have stability around routing. You have an actual path-based routing protocol managing the network, not a loop-free protocol like STP, and routing also doesn’t fail to open and prevents loops with the TTL ( Time to Live ) fields in the headers.

Convergence routing around a failure is quick and improves stability. We also have ECMP ( Equal Cost Multi-Path) paths to help with scaling and translating to scale-out topologies. This allows the network to grow at a lower cost. Scale-out is better than scale-up.

Whether you are a small or large network, having a routed network over a Layer 2 network has clear advantages. However, how we interface with the network is also cumbersome, and it is estimated that 70% of network failures are due to human errors. The risk of changes to the production network leads to cautious changes, slowing processes to a crawl.

In summary, the problems we have faced so far;

STP-based Layer 2 has stability challenges; it fails to open. Traditional bridging is controlled flooding, not forwarding, so it shouldn’t be considered as stable as a routing protocol. Some applications require Layer 2, but people still prefer Layer 3. The network infrastructure must be flexible enough to adapt to new applications/services, legacy applications/services, and organizational structures.

There is never enough bandwidth, and we cannot predict future application-driven requirements, so a better solution would be to have a flexible network infrastructure. The consequences of inflexibility slow down the deployment of new services and applications and restrict innovation.

The infrastructure needs to be flexible for the data center applications. Not the other way around. It must also be agile enough to be a bottleneck or barrier to deployment and innovation.

What are the new options moving forward?

Layer 2 fabrics ( Open standard THRILL ) change how the network works and enable a large routed Layer 2 network. A Layer 2 Fabric, for example, Cisco FabricPath, is Layer 2; it acts more than Layer 3 as it’s a routing protocol-managed topology. As a result, there is improved stability and faster convergence. It can also support massive ( up to 32 load-balanced forwarding paths versus a single forwarding path with Spanning Tree ) and scale-out capabilities.

2nd Lab Guide: VXLAN Basics

In this lab guide, we have a VXLAN overlay network. The core configuration with VXLAN is the VNI, which needs to match on both sides. Below is a VNI of 6002 tied to the bridge domain. We are creating a layer 2 network for the two desktops to communicate. The layer 2 network traverses the core layer, which consists of the spine layer. The use of the VNI allows VXLAN to scale.

VXLAN overlay networking

What is VXLAN?

Suppose you already have a Layer 3 core and must support Layer 2 end to end. In that case, you could go for an Encapsulated Overlay ( VXLAN, NVGRE, STT, or a design with generic routing encapsulation). You have the stability of a Layer 3 core and the familiarity of a Layer 2 core but can service Layer 2 end to end using UDP port numbers as network entropy. Depending on the design option, it builds an L2 tunnel over an L3 core.

A use case for this will be if you have two devices that need to exchange state at L2 or require VMotion. VMs cannot migrate across L3 as they need to stay in the same VLAN to keep the TCP sessions intact. Software-defined networking is changing the way we interact with the network.

It provides us with faster deployment and improved control. It changes how we interact with the network and has more direct application and service integration. Having a centralized controller, you can view this as a policy-focused network.

Many prominent vendors will push within the framework of converged infrastructure ( server, storage, networking, centralized management ) all from one vendor and closely linking hardware and software ( HP, Dell, Oracle ). While other vendors will offer a software-defined data center in which physical hardware is virtual, centrally managed, and treated as abstraction resource pools that can be dynamically provisioned and configured ( Microsoft ).

Summary: SDN Data Center

In the dynamic landscape of technology, data centers play a crucial role in storing, processing, and delivering digital information. Traditional data centers have limitations, but the emergence of Software-Defined Networking (SDN) has revolutionized how data centers operate. In this blog post, we delved into the world of SDN data centers, exploring their benefits, key components, and potential implications.

Understanding SDN

SDN, in essence, separates the control plane from the data plane, enabling centralized network management through software. Unlike traditional networks, where network devices make individual decisions, SDN allows for a more programmable and flexible infrastructure. By abstracting the network’s control, SDN empowers administrators to manage and orchestrate their data centers dynamically.

Key Components of SDN Data Centers

It is crucial to grasp the critical components of SDN data centers to comprehend their inner workings. The SDN architecture comprises three fundamental elements: the Application Layer, Control Layer, and Infrastructure Layer. The Application Layer houses the software applications that utilize the network services, while the Control Layer handles network-wide decisions and policies. Lastly, the Infrastructure Layer comprises the physical and virtual network devices that forward data packets.

Advantages of SDN Data Centers

The adoption of SDN in data centers brings forth a myriad of advantages. Firstly, SDN enables network programmability, allowing administrators to configure and manage their networks through software interfaces. This flexibility reduces manual configuration efforts and enhances overall efficiency. Secondly, SDN data centers boast improved scalability, as the centralized control plane simplifies network expansion and resource allocation. Additionally, SDN enhances network security by enabling fine-grained control and real-time threat detection.

Potential Implications and Challenges

While SDN data centers offer numerous benefits, addressing potential implications and challenges is crucial. One concern is the potential risk of a single point of failure in the centralized control plane. Network disruptions or software vulnerabilities could significantly impact the entire data center. Moreover, transitioning from traditional networks to SDN requires careful planning, as it involves reconfiguring the existing infrastructure and training network administrators to adapt to the new paradigm.

Conclusion:

In conclusion, Software-Defined Networking (SDN) has paved the way for a new era of data centers. By separating the control and data planes, SDN empowers administrators to programmatically manage their networks programmatically, leading to enhanced flexibility, scalability, and security. Despite the challenges and potential implications, SDN data centers hold immense potential for transforming the way we architect and operate modern data centers.

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Statistics don’t lie.

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Lab Guide: STP va Routing Blocking Links

2nd Lab Guide: VXLAN Basics

VXLAN overlay networking

Summary: SDN Data Center

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