
Today’s remote workforce, combined with the evolution of cloud and edge IT environments, necessitates a flexible and scalable networking architecture. The answer comes in the form of a Software-Defined Wide Area Network, or SD-WAN for short. At the same time, this open architecture also creates many security challenges for businesses. SD-WAN security optimization is your solution.
In this article, I’ll explain what SD-WAN is, its challenges, and its many built-in security capabilities. Additionally, I’ll go over some ways you can improve your overall SD-WAN security.
Let’s start with a simple definition.
What Is SD-WAN?
SD-WAN is a virtual architecture geared for cloud and hybrid IT environments. Based on the OpenFlow standard, a communication protocol that provides access to a network’s forwarding plane, you can use it to manage network configurations and security through software. For comparison, traditional networks control traffic and operations through hardware such as firewalls, routers, and switches.
The biggest advantage of SD-WAN is that it supports a virtual and distributed environment consisting of virtual environments, edge devices, and SaaS applications. This advantage allows all users and devices to connect to the enterprise network through the internet. On the other hand, this internet connection model opens up many security issues.
Next, I’ll analyze these issues and their potential impact on your business.
3 SD-WAN Security Challenges
Maintaining SD-WAN security isn’t easy, as the surrounding environment and setup have many associated challenges. Here are some of them:
1. IT Sprawl
Firstly, the current remote working model has added to the IT sprawl. This is because you now have more endpoints that you can use to connect to the enterprise network from different parts of the world. In turn, this translates to multiple opportunities for cybercriminals to enter your organization’s security. Remember, even one unsecured or compromised device can allow access to your network.
2. SD-WAN Selection
Choosing an SD-WAN that best fits your needs requires extensive research, given the many vendors available today. As a result, many businesses find this process time-consuming and confusing.
3. Benefits vs Outcomes
SD-WAN provides many benefits for businesses, such as better connectivity, improved security, and cost savings. However, the outcomes depend on many other factors, such as vendor choice, network layout, etc.
However, things aren’t as bad as they sound because SD-WAN security revolves around many built-in security features that help protect your network from intrusions.
Let’s have a look at SD-WAN security features and capabilities now.
6 SD-WAN Security Features and Capabilities
Every SD-WAN is different, yet, most of them come with the below-mentioned basic security features to protect your network. Consider these when you’re looking to strengthen your SD-WAN security.
1. Data Encryption
As devices transmit data to and from the enterprise network, most SD-WANs come with encryption during transit. They use 128-bit or 256-bit AES encryption to protect the data from unauthorized viewing.
2. TLS-Encrypted Traffic Management
The transport layer of your network encrypts incoming and outgoing traffic to prevent unauthorized eavesdropping and tampering. Moreover, this layer uses Hash-based Message Authentication Code (HMAC) to prevent any data packet from getting altered.
3. Traffic Segmentation
SD-WANs use traffic segmentation strategies to isolate unsecured connections. For example, you can create a new segment for virtual networks that connect from unknown locations. You can implement additional security features such as zero-trust authentication for these new segments. These measures reduce the chances of cyberattacks occurring through unknown devices and locations.
4. Firewalls
All SD-WANs come with a built-in firewall that examines data packets and restricts unauthorized access to your network. Essentially, they filter packets based on ports and source IP addresses and send notifications about data packets from unknown or blocklisted locations. In this sense, they offer protection against layer three threats such as DDoS attacks.
5. IPSec-Based VPNs
All SD-WANs come with IPSec-based VPNs. These VPNs provide a tunnel or a safe passageway for data packets to travel to and from end devices and the corporate network. The VPNs authenticate the sender, receiver, and data packets. In addition to that, they use public and private key encryption to protect your data.
6. Threat Intelligence
SD-WANs leverage artificial intelligence (AI) and machine learning (ML) to provide threat intelligence services to predict impending attacks. You can use this valuable information to take the necessary measures to thwart ransomware and other cyberattacks. Overall, threat intelligence allows you to easily safeguard your resources from any threat.
Undoubtedly, the abovementioned built-in capabilities reduce the possibility of threats, but are they enough to provide comprehensive protection? Unfortunately, no, given the growing sophistication of attacks and the ingenious modus operandi of cyberattackers. This is why you must take additional steps to maintain your SD-WAN security.
In the next section, I’ll discuss how you can improve this security.

How to Improve SD-WAN Security
Along with the built-in SD-WAN security capabilities mentioned above, you should consider implementing the below tools and strategies to provide more comprehensive protection of your network.
Next-Generation Firewalls (NGFWs)
NGFWs are advanced firewalls that go beyond the traditional built-in firewalls that typically come with SD-WANs. They offer a ton of additional protection. For instance, deep packet inspection is a critical feature that examines the contents of data packets and not just the source IP addresses and ports.
Furthermore, NGFWs come with Intrusion Prevention Systems (IPS) that notify your admins about malicious data packets and subsequently block them from entering your network. When you combine these features with application awareness, an NGFW can even block apps that look suspicious. One final aspect is sandboxing, which helps you test unknown data packets in a safe and enclosed environment.
Firewall-as-a-Service (FWaaS)
A firewall-as-a-Service (FWaaS) is a cloud-based NGFW you can use to protect your cloud resources. It’s highly reliable, quickly scalable, and provides increased network visibility through centralized logging. Furthermore, it streamlines access to critical resources, helps with effectively implementing security policies, and more.
Web Application Firewalls (WAFs) And Secure Web Gateways (SWGs)
WAFs and SWGs protect your network from web-based attacks. Regarding SD-WAN setups, thousands of devices connect to your network through the internet. The built-in TLS-encryption capabilities of SD-WANs can’t scale to inspect the traffic that flows from different endpoints. This is why cyberattackers tend to hide their malware inside TLS traffic, as they have a very low chance of getting detected.
Tools like WAFs and SWGs inspect every packet at scale, identify those packets that contain malware, and isolate them. These tools reduce the chances of TLS-based attacks. WAFs and SWGs also complement TLS encryption to boost the safety of web applications.
Continuous Patch Management
Software owners release patches regularly to protect their software from cyberattacks. Install these patches as they become available to protect your devices and applications from imminent attacks. Also, you have many tools available to download and install these patches across all devices on your network.
Regular Backups
Conduct regular data backups so you don’t lose data when your devices crash. These backups can also come in handy in the unfortunate event of a ransomware attack. Security experts even recommend having backups as an integral part of your security strategy. It’s fairly easy to do this, thanks to the availability of many backup services.
Overall, the existing security capabilities of SD-WANs may not be enough to protect your enterprise network from an attack. Consider adding some or all of the abovementioned strategies to improve your network’s security.
Below is a quick recap of everything discussed.
Final Words
To conclude, SD-WANs are a virtual network architecture that allows remote devices to connect to a corporate network through the internet. Most SD-WANs have built-in security capabilities to protect your data from unauthorized access. Also, these security features reduce the chances of attacks and mitigate their impact on the business. That said, these capabilities alone aren’t enough, given the growing sophistication of attackers. This is why I’ve listed a few strategies and tools to improve your business’s SD-WAN security. Feel free to refer to this article should you need a quick refresher!
Do you have more questions about SD-WAN security? Check out the FAQ and Resources sections below!
FAQ
Do I need an SD-WAN for my business?
Yes, most businesses use SD-WAN for integrating their remote workers and diverse endpoints into the corporate network. It has many security capabilities to protect the data that travels between user devices and the enterprise network.
Is SD-WAN the same as a VPN?
No, they’re not the same. Essentially, SD-WANs are a gateway for devices and users to connect to a network securely. On the other hand, VPNs only enable secure point-to-point connectivity. Furthermore, SD-WANs optimize traffic routing while VPNs only use a single network link for all traffic.
Are SD-WANs the same as MPLS?
No, they’re different. A Multiprotocol Label Switching (MPLS) is a dedicated hardware line that offers high bandwidth and low data loss. However, they’re expensive to implement. On the other hand, an SD-WAN is a software-based solution for encrypting and managing traffic from remote devices.
Is SD-WAN secure?
Yes, to some extent, as it comes with many built-in security features and capabilities such as firewalls, encryption, and threat intelligence. However, these capabilities may not be enough to prevent highly sophisticated attacks. This is why you should consider complementing SD-WAN with security tools such as NGFWs.
Is SD-WAN fast and cheap?
Yes. SD-WAN optimizes traffic routing so data packets travel through the shortest path to the destination. This is why SD-WANs are faster than MPLS and traditional networks. Also, they’re cheap because they use software and don’t require extensive hardware installations.
Resources
TechGenix: Article on SD-WAN Trends
Read about the top 4 SD-WAN trends.
TechGenix: Article on Choosing an SD-WAN Provider
Learn how to choose an SD-WAN provider.
TechGenix: Article on SD-WAN vs WAN Optimization
Educate yourself on the differences between SD-WAN and WAN optimization.
TechGenix: Article on MPLS vs SD-WAN
Understand how MPLS and SD-WAN stack against each other.
TechGenix: Article on SD-WAN’s Impact on Businesses
Find out all about SD-WAN’s impact on enterprises.