This chapter covers the following topics:
Networks of Today: This section covers the technologies that are driving changes in the networks of today.
Common Business and IT Trends: This section covers the most common trends that are having a considerable impact on the network.
Common Desired Benefits: This section examines the benefits and desired outcomes that organizations are looking for from a solution.
High-Level Design Considerations: This section covers various aspects of network design and things that affect the deployment and operations of networks today.
Cisco Digital Network Architecture: This section examines from a high level the benefits and drivers of Cisco DNA.
Past Solutions to Today’s Problems: This section covers the technologies used in the past and the challenges associated with them.
Introduction to Multidomain: This section covers the value and benefits of a multidomain environment.
Cloud Trends and Adoption: This section covers the trends and challenges of cloud adoption.
Networks of Today
The IT industry is constantly changing and evolving. As time goes on, there is an ever-increasing number of technologies putting a strain on the network. New paradigms are formed as others are being shifted away from. New advances are being developed and adopted within the networking realm. These advances are being developed to provide faster innovation and the ability to adopt relevant technologies in a simplified way. This requires the need for more intelligence and the capability to leverage the data from connected and distributed environments such as the campus, branch, data center, and WAN. Doing so allows for the use of data in interesting and more powerful ways than ever seen in the past. Some of the advances driving these outcomes are
Artificial intelligence (AI)
Machine learning (ML)
Internet of Things (IoT)
The influx of these technologies is putting a strain on the IT operations staff. This strain comes in the form of requiring more robust planning, agreed-upon relevant use cases, and detailed adoption journey materials for easy consumption. All these requirements are becoming critical to success. Another area of importance is the deployment and day-to-day operations of these technologies as well as how they fit within the network environment. Disruption to typical operations is more immanent with regard to some of these technologies and how they will be consumed by the business. Other advances in technology are being adopted to reduce cost of operations and to reduce complexity. Every network, to some degree, has inherent complexity. Having tools that can help manage this complexity is becoming a necessity these days.
Automation is something that many in the IT industry are striving for, because the networks of today are becoming more and more complicated. Often organizations are operating with a lean IT staff and a flat or diminishing IT budget and are struggling to find ways to increase the output of what the network can do for the business. Another driver for the adoption of these technologies is to improve the overall user experience within the environment. This includes enabling users to have the flexibility and capability to access any business-critical application from anywhere in the network and ensuring that they have an exceptional experience when doing so. In addition to improving user experience, the IT operations staff is searching for ways to simplify the operations of the network.
There are many inherent risks associated with manually configuring networks. There is risk in the form of not being able to move fast enough when deploying new applications or services to the network. Risk could also be seen as misconfigurations that could cause an outage or suboptimal network performance, resulting in impacting business operations and potentially causing financial repercussions. Finally, there is the risk that the business itself is relying on the network for some business-critical services and that they might not be available due to the IT operations staff not being able to keep up with the demand of the business from a scale perspective. According to a Cisco Technical Assistance Center (TAC) survey taken in 2016, 95 percent of Cisco customers are performing configuration and deployment tasks manually in their networks. The survey also stated that 70 percent of TAC cases created are related to misconfigurations. This means that typos or incorrectly used commands are the culprit for a majority of issues seen in the network environment. This is where automation shines. Having the capability to signify the intent of the change that needs to be made, such as deploying quality of service (QoS) across the network, and then having the network automatically configure it properly, is an excellent example of automation. This accomplishes configuring services or features with great speed and is a tremendous value to the business. Simplifying operations and reducing human error ultimately reduces risk.
A simple analogy for network automation would be to think of an automobile. The reason most people use an automobile is to meet a specific desired outcome. In this case, it would be to get from point A to point B. An automobile is operated as a holistic system, not a collection of parts that make up that system, as depicted in Figure 1-1. For example, the dashboard provides the driver all the necessary information regarding how the vehicle is operating and the current state of the vehicle. When the driver wants to use the vehicle, certain operational steps are required to do so. The driver simply signifies the intent to drive the car by putting it in gear and using the system to get from point A to point B.
Figure 1-1 Automobile as a System (Image Courtesy of Bubaone/Getty Images)
Why can’t networks be thought of in the same way? Thinking of a network as a collection of devices, such as routers, switches, and wireless components, is what the IT industry has been doing for over 30 years. The shift in mindset to look at the network as a holistic system is a more recent concept that stems from the advent of network controllers—the splitting of role and functionality from one another. The most common description of this is separating the control plane from the data plane. Having a controller that sits on top of the rest of the devices, so to speak, gives the advantage of taking a step back and operating the network as a whole from a centralized management point. This is analogous to operating an automobile from the driver’s seat versus trying to manage the automobile from all the pieces and components that it is derived from. To put this in more familiar terms, think of the command-line interface (CLI). The CLI is not designed to make massive-scale configuration changes to multiple devices at the same time. Traditional methods of managing and maintaining the network aren’t sufficient to keep up with the pace and demands of the networks of today. The operations staff needs to be able to move faster and simplify all the operations and configurations that have traditionally gone into networking. Software-defined networking (SDN) and controller capabilities are becoming areas of focus in the industry and are evolving to a point where they can address the challenges faced by IT operations teams. Controllers offer the ability to manage the network as a system, which means policy management can be automated and abstracted. This provides the capability of supporting dynamic policy changes versus its predecessor of manual changes of policy and configurations on a device-by-device basis when something requires a change within the environment.