Software-Defined Access: A Complete Guide

An image of a world that's encompassed by a network of lines.
Manage remote access with SD-Access.
Source: Geralt at Pixabay

Many transformational changes—like the work-from-anywhere culture and the Internet of Things (IoT)—have changed networks. Additionally, as networks evolve and adapt to these changes, organizations strive to have complete control over who has access to the network. This visibility prevents unauthorized access and reduces the threat of cyberattacks. To meet this need for streamlined and granular control over network access, Cisco created software-defined access (SD-Access).

Read on as I talk about SD-Access, its benefits, limitations, and how it works. I also talk about how SD-Access compares with other authorization measures and how you can implement it for your organization. Let’s start with the basics.

What Is Software-Defined Access

Simply put, SD-Access provides complete control and visibility into your networks using policy-based automation and software. Moreover, it comes with the tools needed to onboard, segment, and provide access to your organization’s resources for authorized employees. You can even automate user and device policy across wired and wireless networks for streamlined access. 

Software-defined access addresses multiple challenges like network security, varying infrastructure, and operational control across departments. Additionally, it enables you to build next-gen networks that are fast, easy to manage, and that offer high levels of efficiency.

Here’s a detailed look at the benefits of SD-Access.

5 SD-Access Benefits

An image of a businessman using a fingerprint on a screen with the word security in the foreground.
Manage secure access in your company.
Source: geralt at Pixabay

SD-Access offers many benefits for employees, IT admins, and the organization; including the following 5:

1. Enhanced Productivity

With SD-Access, you can automate network and resource access for your employees. As a result, an authorized employee can access your network and the resources they need for work. In turn, the unhindered access to resources can vastly improve their productivity.

More importantly, SD-Access creates a streamlined experience for your employees as they no longer have to wait for access. As an IT admin, you can even automate this access control based on users and devices.

2. Wide Range of endpoints

One of the benefits of SD-Access is that it brings different endpoints into your IT fold. The endpoints can be employees’ devices, industrial devices, IoT devices, and so much more. In this sense, SD-Access goes beyond traditional networks and enables you to access any network.

3. Simplified Segmentation

With SD-Access, you can separate access based on user, device, and application. You do all this using the underlying software, so your networks don’t need redesigning to meet new access requirements. 

Also, it creates an agile infrastructure that can be controlled and segmented through software. Moreover, you can apply uniform security policies across different segments and networks. To this end, you can reduce your operational expenses. 

4. Detailed Insights

SD-Access provides you with monitoring and logging capabilities. Both can help you better understand how your network works. Accordingly, you can make the necessary changes for capacity planning and budgeting. Also, these insights can quickly point out potential threats you can address. 

5. Streamlined Compliance Processes

SD-Access can help you comply with leading security standards. You can even generate the necessary usage reports for auditing. From these audit reports, you can then make relevant changes to meet compliance. 

The above benefits clearly show why software-defined access is the future. However, it also comes with some pitfalls, and understanding them is equally important.

3 SD-Access Limitations

SD-Access has its share of limitations, with the main 3 described below.

1. Need Professional Expertise

You can leverage the benefits of SD-Access only when it’s well configured. Essentially, you need an expert IT admin who can set up the groups and protocols, configure the user access controls, and segment the network. Finding experts can be problematic and add to your operational costs as well.

2. Complex Implementation

SD-Access is complex to implement, and you always risk misconfiguration. Though expert admins can quickly resolve these misconfigurations, it could take time and effort.

3. Evolving

SD-Access isn’t a new technology, but it’s been adapted to meet the changing needs of any business. In this sense, software-defined access is still evolving as it may change to meet future requirements.

Despite these limitations, SD-Access works better than many other authorization measures used today, and in the next section, we’ll see how.

How Does SD-Access Compare to Other Authorization Measures?

An illustration of a businessman touching the word access.
Access to only authorized users.
Source: mohamed_hassan on Pixabay

SD-Access is undoubtedly better than many standard authentication measures such as two-factor authentication, biometrics, etc. Typically, standard authentication measures check only identity, and only while entering the network. Beyond that, it doesn’t check what the user or device accesses.

SD-Access, on the other hand, provides granular control over access, so you can set the resources that a particular user or device can access within the network. You can even give access to only specific applications relevant to the user. Such granular control isn’t possible with other authorization measures. 

Now this discussion can make you wonder how SD-Access provides such granular control, and that’s what I’ll discuss next.

How Does SD-Access Work?

Software-defined access uses 3 components to implement secure authentication and streamlined access. We’ll discuss these below.

1. Edge Access Control

Edge access control is similar to the authentication measures we discussed earlier, like two-factor authentication. This component is responsible for verifying the identity of the user or device. It also allows them access to the network accordingly. However, the main difference is that the edge access control is dynamic in SD-Access. It can be changed when needed, while it’s static in other authentication measures. A related advantage is you can isolate a port and quarantine it in the event of an attack, so the rest of your network is safe. 

2. Central Policy Engine

The central policy engine is the heart of SD-Access. This engine creates Access Control Lists (ACLs) and pushes them to the edge switches. In turn, the switches authenticate devices and users based on this list. Using a central policy engine, you can create any level of security and authorization, starting from open access to zero trust. In short, zero trust is a security measure that blocks access unless permitted explicitly.

3. Behavioral Analysis

Behavioral analysis assesses the behavior of known threats and compromised systems and informs the central policy engine. Accordingly, the policy engine directs ports to block or quarantine access for the infected device.

Together, these 3 components provide dynamic security access for the relevant users and devices while blocking malicious entities. Next, let’s talk about the hands-on implementation of SD-Access.

How to Implement SD-Access in Your Business 

You can implement software-defined access using your access to appropriate Cisco switches and routers. In particular, you must use the Cisco Identity Services Engine (ISE) as it delivers an identity-based policy for users and devices. The DNA Center (DNAC) is also an important component and provides management and automation through a GUI. Wireless APs are also needed if you want to extend SD-Access to wireless networks. Once you subscribe to these components, your IT admin can configure SD-Access for your organization. 

I hope that was insightful. Here’s a quick recap before I end.

Final Thoughts

Networks are constantly expanding and evolving and this means you need a dynamic way to secure access to your network. Software-defined Access (SD-Access) fits this requirement well and provides the authentication, visibility, and control you need to ensure that only authorized users access a particular resource. It helps with threat analysis and compliance as well. In this article, we talked extensively about the benefits, limitations, working, and implementation of software-defined access. I hope this information helps you to make an informed decision when it comes to your network security.

Do you have more questions about software-defined access? Check out the FAQ and Resources sections below!


Are SD-WAN and SD-Access the same?

No, they aren’t the same. Though SD-WAN and SD-Access fall within software-defined networking, they aren’t synonyms. SD-Access is used to configure the architecture of LAN networks. Conversely, SD-WAN is all about creating next-gen WAN with extensive automation features. 

Where can I implement SD-Access?

You can implement SD-Access in any LAN, though it’s best suited for campus and branch networks. It’s not a good choice for WANs and data centers. In fact, SD-WAN is a better choice for those networks. SD-Access is also highly useful for automating access and improving the automation capabilities, streamlining access. 

Can SD-Access provide zero trust security?

Yes, SD-Access can provide zero trust security. Its central policy engine can notify the edge switches to block all access unless explicitly specified. This way, every user or device has to go through the authentication process to gain access. Besides this, you can also enforce policies uniformly across the entire network. 

Do I need Cisco ISE to implement SD-Access?

Yes, Cisco ISE is a must-have component. That’s because it’s the central engine that sends Access Control Lists (ACLs) to the edges. Along with ISE, you also need Cisco DNA to implement SD-Access in your organization. Some other components you need are Cisco routers and switches that are compatible with Cisco ISE and DNA. 

Is SD-Access a virtualization layer?

Yes, SD-Access is a virtualization layer that sits between the network and users who want to access it. Essentially, it compares the identity of the user or device against a set of ACLs; allowing or blocking access. This process is dynamic and can also be extended to individual applications. 


TechGenix: Article on Cybersecurity Jobs

Learn more about the latest cybersecurity jobs

TechGenix: Article on the Top Use-Cases for SD-WAN

Know the top use-cases of SD-WAN

TechGenix: Article on the Working of SD-WAN

Educate yourself on the working of SD-WAN.

TechGenix: Article on Remote Network Access

Read all about remote network access.

TechGenix: Article on Zero Trust Network Access

Know what’s zero trust network access.

About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Scroll to Top