Networking

How Large Business Can Secure Their Software-Defined WANs

Wide area networks offer enterprise benefits for IT management at scale. But wider networks mean bigger risks.

Doug Bonderud is an award-winning writer capable of bridging the gap between complex and conversational across technology, innovation and the human condition.

Software-defined wide area networks (SD-WANs) have enjoyed substantial enterprise uptake over the past few years as organizations look to streamline IT management, improve visibility and enhance overall control.

However, as networks expand in scope and scale, so do potential cybersecurity risks. While SD-WAN deployments offer some inherent structural security benefits over their hardware-defined counterparts, companies can’t afford to rest on these laurels. Instead, it’s essential to leverage security best practices that help build on existing SD-WAN advantages and better defend corporate network connections.

What Is a Software-defined WAN?

SD-WAN solutions decouple hardware-based control plane functions from key network operations. This abstraction makes it possible to create a virtualized network overlay capable of monitoring and managing network functions, in turn allowing SD-WAN devices to choose the best network paths for specific applications.

As a result, software-defined wide area networks are more agile and less costly. Virtualized resources are easier to assign, adjust and automate than their hardware-driven counterparts, while the inherently agnostic nature of decoupled transport technologies means companies can avoid the often substantial costs of proprietary process offerings.

In addition, SD-WANs offer better overall performance because they can be easily configured to select the best network path from multiple options rather than relying on predefined routing roadmaps.

The Inherent Security Benefits of Software-Defined WANs

SD-WAN deployments offer direct benefits for business security strategies. As noted by Network World, SD-WANs significantly reduce the complexity of VPN management by eliminating the need for multiple firewalls thanks to the use of full-mesh network communication.

Software-defined solutions also allow companies to directly implement specific security functions rather than using third-party programs to address key risks. For example, SD-WANs are inherently capable of permitting or denying traffic to specific sites or limiting the total amount of traffic to help defuse the threat of distributed denial of service attacks. Virtual firewall solutions, meanwhile, can be deployed directly into SD-WAN frameworks, allowing companies to pass on physical firewall devices.

The Risks of Insecure WANs

While the decoupled nature of software-defined WANs helps limit the risk of hardware-based threats, enterprises can’t fall into the trap of assuming that deployment of SD-WANs is enough to secure networks at scale.

When it comes to wide area network protection, organizations must ensure they account for potential risks, including:

Obfuscated onboarding: As TechTarget points out, onboarding new SD-WAN solutions can increase security risk, especially if companies are using a hybrid or public cloud service model. Without clear knowledge of where network control devices are stored, how they’re protected and who has access, seemingly secure SD-WANs could introduce potential points of compromise.
Reduced rigor: Because SD-WANs offer built-in security structures, they’re often overlooked when it comes to the rigorous security testing applied to other IT components. As a result, it’s critical for companies to regularly test SD-WANs to identify possible weak points — such as authentication or access requirements — and address them before they’re exploited.
Cutting corners: Not all SD-WANs are created equal. Just as cloud computing markets have diversified to include a mixture of high-end, midrange and low-budget options, SD-WAN providers offer similar solution variety. And while budget-friendly frameworks may provide familiar functionality¸ they often come up short in traffic management and monitoring.

Extra Steps to Ensure WAN Security

To ensure SD-WANs deliver maximum security, three steps are critical:

Consider the big picture: SD-WANs don’t just simplify management and improve connectivity — they’re also part of the larger security landscape. As a result, companies must design and deploy consistent, policy-based rulesets that include SD-WAN operations.
Leave legacy behind: While legacy firewalls deployed at the individual office level or as part of data backhauls to enterprise data centers are cornerstones of traditional WAN frameworks, they introduce both performance and protection problems for SD-WANs. To improve decoupled network security, companies must leave legacy firewalls behind.
Diversify defensive capabilities: Just as cloud vendor lock-in can hamper corporate agility, single-source security can frustrate defensive efforts. Defensive diversity across SD-WAN components and connections is critical for comprehensive protection.

Software-defined WANs offer inherently improved defense derived from decoupled network functions, but this isn’t enough to secure enterprise IT environments at scale. Companies must also integrate SD-WAN solutions into broader security frameworks, deploy next-generation firewall technologies to account for increased attack surfaces and avoid asset lock-in to ensure agile response.

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