Home > Articles > Today's Networks and the Drivers for Change

Today's Networks and the Drivers for Change

Chapter Description

In this sample chapter from Cisco Software-Defined Access, you will find a high-level overview of how the networks of today are causing challenges for organizations and their operations staff,

From the Book

Cisco Software-Defined Access

Cisco Software-Defined Access

$47.99 (Save 20%)

High-Level Design Considerations

Considering the complexity of a majority of the networks out there today, they can be classified in a couple categories such as redundant and nonredundant. Typically, redundancy leads to increased complexity. Often, the simplest of networks do not plan for failures or outages and are commonly single-homed designs with multiple single points of failure. Networks can contain different aspects of redundancy. When speaking strictly of the campus LAN portion of the environment, it may include redundant links, controllers, switches, and access points. Table 1-1 lists some of the common techniques that are introduced when dealing with redundancy.

Table 1-1 Common Redundancy Techniques

Redundant Links

Redundant Devices

Administrative distance


Traffic engineering

Loop prevention

Preferred path selection

Preferred path selection

Prefix summarization

Advanced filtering



Many redundancy options are available, such as redundant links, redundant devices, EtherChannel, and so on. Having a visual of what some of these redundancy technologies look like is often helpful. One of these technologies is Cisco Virtual Switching System (VSS), which bonds switches together to look and act like a single switch. This helps put into context how the network will need to be configured and managed to support these types of redundancy options. The following are some of the benefits of VSS technology:

  • Simplifies operations

  • Boosts nonstop communication

  • Maximizes bandwidth utilization

  • Lowers latency

Redundancy can take many different forms. VSS is used for much more than just redundancy. It helps with certain scenarios in a campus design, such as removing the need for stretched VLANs and loops in the network. Figure 1-2 showcases an example of a campus environment before and after VSS and depicts the simplification of the topology.


Figure 1-2 VSS Device- and Link-Based Redundancy Options

Outside of the complexity associated with redundancy, there are many other aspects of the network that cause complexity within a network environment. Some of these aspects can include things such as securing the network to shield it from malicious behavior, leveraging network segmentation to keep traffic types separate for compliance or governance reasons, and even implementing QoS to ensure optimal application performance and increase users’ quality of experience. What further complicates the network is having to manually configure these options. The networks of today are too rigid and need to evolve. The industry is moving from the era of connectivity-centric network delivery models to an era of digital transformation. There is a shift required to transition to a digital transformation model. The shift is from hardware- and device-centric options to open, extensible, software-driven, programmable, and cloud-enabled solutions. Figure 1-3 depicts the transition in a simple summary. Relying more on automation to handle the day-to-day operational tasks and getting back time to focus on how to make the network provide value to the business is crucial to many organizations. This is delivered through policy-driven, automated, and self-optimizing capabilities. This provides closed-loop, automated service assurance that empowers network operations staff to transition from a reactive nature to a more proactive and predictive approach. Freeing up more of the operations staff’s time should enable them to focus on more strategic initiatives within the business.


Figure 1-3 Digital Transformation Transition

Intent-based networking (IBN) is taking the IT industry by storm. The concept revolves around signifying the intent of the business and automatically translating that intent into the appropriate corresponding networking tasks. This is a circular logic in that it captures the intent of the business and IT staff and then translates that intent into the appropriate policies that are required to support the business. Once the policies are created, the next step is to orchestrate the configuration of the infrastructure. This includes both physical and virtual components. This then kicks off the final step, which is providing assurance, insights, and visibility to ensure the network is functioning properly. Because this is a loop in a sense, the logic uses continuous verification and supplies any corrective actions that are necessary to fix or enhance the network’s performance. Figure 1-4 illustrates the intent-based networking model.


Figure 1-4 Intent-Based Networking

Analytics and insights are absolutely critical to networks of today. Typical network management systems (NMSs) do not provide the necessary information to resolve issues in a quick and efficient manner. They are reactive in nature and don’t supply the predictive monitoring and alerting that organizations require. Simple Network Management Protocol (SNMP) Traps and SYSLOG messages are valuable but haven’t been used as well as they could be. Reactive notifications mean that the issue or fault has already happened and don’t prevent any impact to the business. Often, there are false positives or so many alerts that it is difficult to determine what information should be acted upon or ignored completely. Traditionally, the network operations workflow has been similar to the following:

  1. Receive an alert or helpdesk ticket.

  2. Log in to the device(s) to determine what happened.

  3. Spend time troubleshooting.

  4. Resolve the issue.

The days are over of hunting around and searching through log files and debugging traffic to determine what the issue is that has caused an outage to the network. The amount of data that runs through these networks and has to be sorted through to chase down an issue is exponentially increasing. This is leading to the manual sifting through information to get to the root cause of an issue being extremely more difficult than ever before. Organizations rely on information relevant to what they are looking for; otherwise, the data is useless. For example, if a user couldn’t get on the wireless network last Tuesday at 3 p.m., and the logs are overwritten or filled with non-useful information, how does this help the network operations staff troubleshoot the issue at hand? It doesn’t. This wastes time, which is one of the most precious resources for network operations staff. The dichotomy of this is using analytics and insights to help direct network operators to the right place at the right time to take the right action. This is part of what Cisco DNA Assurance does as part of intent-based networking.

Problem isolation is much easier within an intent-based network because the entire network acts as a sensor that provides insights into the failures that are happening in the network. The network also has the capability to have a holistic view of the network from a client perspective. From a wireless perspective alone, this can provide information such as failure reasons, received signal strength indicator (RSSI), and onboarding information.

One of the most time-draining parts of the troubleshooting process is trying to replicate the issue. The previously mentioned issue of a user not being able to get on the network last Tuesday at 3 p.m. would be very difficult to replicate. How would anyone know what possibly was going on last Tuesday at 3 p.m.? In reality, the only traditional way to know what was going on from a wireless perspective was to have constant packet captures and spectrum analyzers running. Due to cost, space, and not knowing where the issue may arise, this is not a practical approach. What if instead there was a solution that could not only act as a DVR for the network but also use streaming telemetry information such as NetFlow, SNMP, and syslog and correlate the issues to notify the network operations staff of what the issue was, when it happened—Even if it happened in the past? Imagine the network providing all this information automatically. Additionally, instead of having Switched Port Analyzer (SPAN) ports configured across the campus with network sniffers plugged in everywhere in hopes of capturing the wireless traffic when there is an issue, imagine the wireless access points could detect the anomaly and automatically run a packet capture locally on the AP that would capture the issue. All these analytics could provide guided remediation steps on how to fix the issue without requiring anyone to chase down all the clues to solve the mystery. Fortunately, that solutions exists: Cisco DNA Assurance can integrate using open APIs to many helpdesk ticketing platforms such as ServiceNOW. The advantage of this is that when an issue happens in the network, Cisco DNA Assurance can automatically detect it and create a helpdesk ticket, add the details of the issue to the ticket as well as a link to the issue in Assurance, along with the guided remediation steps. That means when the on-call support engineer gets the call at 2 a.m., she already has the information on how to fix the issue. Soon, automatic remediation will be available, so the on-call person won’t have to wake up at 2 a.m. when the ticket comes in. This is the power of Assurance and intent-based networks.

5. Cisco Digital Network Architecture | Next Section Previous Section

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@ciscopress.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.ciscopress.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020