How to Improve SD-WAN Security?
Aug 3, 2022
How to Improve SD-WAN Security?

As the contemporary workforce becomes more mobile and businesses stretch out and flourish, software-defined wide area networks (SD-WAN) have emerged as a popular networking option.

SD-WAN provides companies with greater flexibility, scalability, performance, and agility for today's virtual, edge, branch, and cloud IT environments by bringing the benefits of software-defined networking (SDN) to traditional hardware-centric networks. However, in addition to the benefits SD-WAN brings enterprises, it also introduces a new set of security issues.

This article examines the security features of SD-WAN systems as well as ways to improve SD-WAN cybersecurity. Continue reading for a technical overview of SD-WAN.

What is SD-WAN?

SD-WAN is a virtual architecture for managing a wide-area network that spans the dispersed, hybrid IT infrastructures that are common in today's business enterprises.

Unlike previous WAN designs, which routed all traffic via a central hub or data center, SD-WAN architectures improve the performance of on-premises services such as SaaS apps by providing direct access to cloud platforms. This cloud-centric paradigm offers administrators comprehensive network control capabilities while maximizing bandwidth and lowering service delivery costs.

Software-Defined Networks(SDN) vs. Traditional Networks 

Traditional networks, as defined by veteran system administrators, are the essential gear – switches, routers, and firewalls – that link and govern network traffic for an enterprise. In traditional networks, the control plane (protocols and configuration) and the data plane (forwarding) are the same, allowing managers few options other than physically changing or resetting network equipment.

By contrast, software-defined networks (SDN) separate the control plane and data plane and allow administrators the ability to change network configurations using a software program. SDN leverages contemporary virtualization and remote network administration capabilities while reducing unnecessary travel and setup expenses.

The OpenFlow standard serves as the foundation for SDN, allowing an SDN controller to link and operate switches and ports for network management.


SD-WAN designs are examples of SDN technology used to connect geographically dispersed wide-area networks using broadband internet, multiprotocol label switching (MPLS), 4G/LTE, and 5G.

SDN expressly refers to the separation of control and data planes within the core network, data center, or LAN. SD-WAN, on the other hand, is application routing expanded to a dispersed network of branch offices and users.

SD-WAN Security Challenges

Branch employees and distant users connect to a company network via an internet-linked web of connected devices using SD-WAN topologies. This IT sprawl and an overabundance of endpoints complicate network security. Without sufficient segmentation, even a single unprotected access point might be hazardous.

While SD-WAN solutions have security capabilities out of the box, this is insufficient for safeguarding business workloads across a broadly spread network.

Administrators can first inventory the existing or prospective SD-WAN solution's security features to assess extra security coverage. However, the Secure Access Service Edge (SASE), or the combination of SD-WAN with a set of network security solutions that span edge to cloud security, has become the industry consensus.

The sections that follow examine standard SD-WAN security features, followed by how enterprises might supplement SD-WAN infrastructures with SASE and other solutions.

SD-WAN Security Capabilities and Features

Not all SD-WAN solutions are created equal, but they all have some level of security features. Most include a few security features built in to provide basic network security, such as Internet Protocol Security (IPsec), Virtual Private Networks (VPN), stateful firewalls, and fundamental threat detection and response.

Data Encryption in Transit

As the number of devices and people connected to workplace networks grows, so does the attack surface of sent data.

Many software-defined networking (SDN) systems have 128- and 256-bit AES encryption as well as IPsec-based VPN features. These secure information-in-transit tunnels prevent illegal network access and maintain continuous compliance.

Traffic Segmentation

SD-WAN segmentation enables administrators to divide traffic based on application characteristics and network policies.

Segmenting virtual networks within the SD-WAN overlay prevents traffic from less secure places from infiltrating other segments with sensitive access or data. With this increased flexibility over traditional networks, administrators may build a micro-segmentation plan and integrate zero trust concepts.

Threat Detection and Response

Many SD-WAN providers give access to threat intelligence services that can detect and mitigate typical security risks automatically. Many of these services utilize artificial intelligence and machine learning (AI and ML) to identify suspicious patterns in network traffic and forecast potential security breaches.

Enhancing SD-WAN Security

The security inherent with SD-WAN is insufficient. It provides basic security to clients, but companies must take further steps to identify and remediate increasingly sophisticated attacks. Given the breadth of SD-WAN topologies, the next step is to bridge coverage gaps with suitable security capability.

Next-Generation Firewalls (NGFW) and Firewall-as-a-Service (FWaaS)

Most SD-WAN systems contain a firewall, although they are usually stateful firewalls that simply provide packet filtering and Layer 3 protection. These firewalls may successfully limit illegal access based on IP addresses and ports, but they lack the end-to-end coverage that distributed companies demand.

For business network traffic, next-generation firewalls (NGFW) are crucial. The most recent firewalls include sophisticated features such as:

  • Intrusion detection and prevention systems (IDPS)
  • Data loss prevention (DLP)
  • Deep packet inspection (DPI)
  • Sandboxing

Firewalls-as-a-Service (FWaaS) is a cloud-based next-generation firewall (NGFW) that is ready to control traffic at important cloud access points. NGFW and FWaaS technologies are both critical in establishing micro-segmentation in the cloud-based security age.

Examining Web Traffic

Experienced network administrators recognize the need to examine all network traffic. However, because TLS-encrypted data accounts for the majority of internet traffic, it is significantly more difficult to analyze at scale. As a result, hackers frequently conceal malware in SSL/TLS transmission, knowing that it is less likely to be detected.

Fortunately, options for intercepting TLS interactions between the server and the client are available. After that, the communication is encrypted and analyzed using antivirus scanning and web filtering. Once cleared, the traffic is sent to its final destination.

When it comes to online security, web application firewalls (WAF), secure web gateways (SWG), and cloud access security brokers (CASB) are all viable options.

Patching Systems Quickly

Threat actors are always seeking new methods to break into networks. As a result, software and firmware vendors frequently offer updates and patches to resist hackers' attempts. Unfortunately, these updates do not always happen automatically or at the required frequency.

It is crucial that administrators keep up with upgrades, especially for popular apps and key servers. Learn more about the Best Patch Management Software and Tools from eSP.

Backups and a strict backup policy are other critical pieces of the network security jigsaw since they ensure that lost data may be recovered when all else fails. Backups also provide more flexibility in reacting to an increasingly common reality for businesses of all sizes: ransomware assaults.


SASE combines SD-WAN with the Secure Services Edge (SSE), or the solutions that enable business network security from the edge to the cloud. Though there is no formal list of SSE tools, common components include several of the tools mentioned above, such as FWaaS, SWG, and CASB, as well as:

  • Advanced threat protection
  • Bandwidth and application control
  • Browser isolation
  • Cloud security posture management (CSPM)
  • Encryption and decryption
  • Unified threat management (UTM)
  • Zero trust network access (ZTNA)

Securing Today's Enterprise Networks with SD-WAN

Many leading SD-WAN providers are continuing to implement SASE capabilities in order to increase customer exposure in the nascent secure SD-WAN industry. Meanwhile, some network security firms are deploying security appliances to enable SD-WAN.

Because of the all-encompassing nature of the SD-WAN or SASE solution bundle, things become complicated. As previously said, standalone SD-WAN solutions frequently provide a basic degree of protection, but SASE addresses the whole spectrum of edge-to-cloud security requirements. Customers must choose between pure SD-WAN, pure SSE, and SASE suppliers who provide both capabilities.

Many SD-WAN vendors will position their offering as a complete SDN and security solution. Still, leaving too many variables to a single vendor can be hazardous to enterprise business.

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