Legacy networks, older infrastructures built on outdated hardware and OSes, have many limitations compared to modern networks and pose significant business risks.
Despite their risks, legacy networks persist due to the following:
- Engineers rely on existing skill sets to maintain networks.
- Organizations don't have the budget to allocate toward a network upgrade.
- Executives don't recognize the importance of funding new purchases for the network.
Neglecting to upgrade an outdated network, however, is a critical mistake organizations can't afford to make. The continued use of a legacy network creates management complexities, business risks and higher costs. This article examines the risks of legacy networks, the benefits of transitioning and best practices to get started.
The limitations of legacy networking
Many organizations still use legacy networks, but they come with limitations that prevent them from reaching their full potential. Examples of limitations include the following:
- Device management complexity. Legacy networks use tools that parse human-readable command-line interface text. Because these legacy devices lack APIs, it's difficult to integrate them with modern automation platforms.
- Performance bottlenecks. Legacy devices lack application-specific integrated circuit-based acceleration that is required for advanced networking features. As a result, AI workloads in high-performance environments might not have access to low-latency communication. Combined with low network interface card bandwidth, this creates a data transfer bottleneck.
- Legacy hardware. Vendors often stop sending software updates to old devices. These devices use older wireless encryption standards, such as WPA2, because their hardware cannot support WPA3. These older standards lack newer features modern networks require.
Business risks of legacy networks
When legacy networks are used today, their limitations translate into real operational and business risks. These risks include the following:
- Vulnerable to attacks. Outdated encryption and unpatched devices can expose a network to attacks. For example, Wi-Fi devices that still use WPA2 pose a significant risk when WPA3 is available in newer models.
- Loss of revenue. Because legacy networks are more susceptible to attacks, these hacks can cause network downtime and service disruption.
- Operational inefficiency from silos. Virtual devices in public clouds and physical on-premises devices are two different silos. Manually configuring each of these silos increases the risk of human error.
The cost of inaction
Legacy networks can incur various financial and operational costs for organizations due to outdated infrastructure. Examples include the following:
- Modern applications limited by legacy networking. If an organization tries to modernize applications by adopting Kubernetes or using open source software tools, the disparity between the legacy network and the new technologies could present challenges. Examples include forced reliance on disparate load balancers, lack of zero-trust security, insufficient fine-grained traffic control and limited observability at the application level.
- Inability to automate. Legacy networks have limited automation capabilities, which means network teams complete tasks manually. Teams will become slower to perform device upgrades or troubleshoot.
- Barriers to AI adoption. Over time, the inability to use higher-performance networking infrastructure compounds into a structural disadvantage. Organizations will stagnate as their competitors continuously improve their services with AI.
- Competitive disadvantage. The inability to use new networking technologies leads to the loss of first-mover advantage. Organizations could be outpaced by competitors in digital product releases.
Moving beyond legacy networks
To successfully transition from legacy networking architectures, organizations should follow key best practices. Recommendations include the following:
- Assess and prioritize workloads. Identify high-throughput and low-latency applications. This ensures the network team knows exactly how much capacity and performance the upgrades must deliver.
- Adopt automation and programmability. Purchase devices that support APIs, and ask engineers to learn Python to become familiar with network automation and AI. If part of a workload runs in a public cloud, use orchestration platforms to automate configuration across both environments.
- Ensure security by design. Purchase devices with modern encryption, such as WPA3. For application-level security, use mutual TLS encryption in service meshes.
- Transition in phases. A phased transition enables the organization to continue operating without network disruption.
By following these recommendations, organizations can transition outdated legacy networks into modern networking architectures.
Charles Uneze is a technical writer who specializes in cloud-native networking, Kubernetes and open source.
