Retail and banking technology professionals are keenly aware of the large number of devices that connect to their enterprise's network via Ethernet and Wi-Fi. IT sprawl at each branch adds complexity to network visibility and security, and that complexity means increased risk of a breach. Endpoint security alone, without proper edge security, won't be enough to reduce these risks — and even a next-generation firewall service isn't always enough to secure the perimeter.
As a result, organizations are breached because they fail to detect the threat early enough to respond rapidly and effectively. Traditional security solutions are simply not adequate for the level of visibility and control that are required to mitigate today's threats.
The typical bank IT system, for example, uses multiple financial applications as well as video and voice to enable services such as kiosks for consumers to conference with financial experts miles away.
These branches also need to access financial applications that are hosted in the cloud. Connecting all the bank branches or branch offices of a retail company at a reduced bandwidth cost is the crux of the answer. However, the near-real-time nature of the application puts enormous demands on the network to deliver guaranteed performance without risking the data's security or integrity.
Because of this, enterprises such as finance and retail have begun examining the role of software-defined networking as a best practice for their future IT needs, particularly as it relates to security.
Software-defined wide area networking (SD-WAN) addresses flexibility with transport independence and enables connections over direct Internet broadband as well as multiprotocol label switching (MPLS) circuits and LTE/5G. SD-WAN with multicloud connectivity in particular has allowed enterprises to seamlessly move data and workloads from data centers to the branches to the public cloud. [Editor's note: The author's company is one of many that offer services in this area. See Gartner's Magic Quadrant report for more information.]
The flexibility of the application access that SD-WAN provides from end to end, however, comes with a price if not properly secured: That is, security breaches can occur from anywhere, especially from the branches. The "local Internet breakout" feature — the ability for a branch to work over the Internet without needing to backhaul to the data center — creates a specific need to secure the Internet breakout link. This means enterprises, such as retailers or banks, need to evolve their branch security, in particular, with the overall threat landscape in mind.
Luckily, SD-WAN puts a premium on security, due to the regulatory environment and the need to keep customer data safe and secure. For example, every link is encrypted via IPSec in order to secure the content. This ability to segment traffic is essential for ensuring that credit card transactions are protected from untrusted traffic. Going beyond the Payment Card Industry Data Security Standard compliance is the best possibility to close those unused links and prevent rogue devices from connecting to the network via Ethernet.
Ideally, SD-WAN can use policies to automate security assurance and can take automatic remedial security actions based on suspicious network behavior that is detected in real time and without user action.
Consider a scenario where a customer needs to have guest access at a bank branch or at a retail shop. Once this access is provided, that user's file downloads need to be quarantined for viruses and other threats. Embedded intrusion prevention and detection systems (IPS/IDS) and antivirus functionality are needed at the branch network where this Wi-Fi connection is going to be established. URL/web filtering is also necessary to prevent this guest user from accessing unwanted and potentially virus-laden websites.
The prevention of this unwanted access is also not just limited to the guest users. It can be applied to the bank or retail shop employees as well in restricting access to specific websites and unauthorized access to things such as corporate data centers, for example. With security policies defined per user group or retail location, such access can be controlled.
A truly flexible SD-WAN security implementation should not just mandate embedded security; it should also provide the flexibility to supplement any onboard security from the SD-WAN vendor with additional features from the cloud security vendor. When a traffic flow needs to be further scrubbed, this approach then allows it to be redirected to the security measures deployed in the cloud. As part of the automatic response to a threat, it is important to dynamically insert a security service for suspected traffic. This dynamic insertion may involve instantiation of a security virtual network function within the customer premises equipment at the branch.
To prevent further security attacks, one needs visibility into what is happening on the network today. The visibility and analytics should provide reports and alerts based on security policy violations, byte/packet count of the volumetric distributed denial-of-service attack, number of accesses to malicious sites, user/location-based activity, etc. These reports help in-network forensics and troubleshooting as well.
Enterprises currently consider SD-WAN to be a best practice because of its flexibility, scalability, performance, and agility to deploy and manage a larger number of branches; there also is embedded security in SD-WAN branches and the controller.
Because of its security functions (such as a stateful firewall, URL/web filtering, IPS/IDS, visibility and analytics at the link level as well as the application level), SD-WAN provides security for today's vast landscape of IT connections from the data center to the branch to the cloud, aiding an enterprise's journey toward digital transformation.
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