Imagine walking into the office early on what you think is going to be a normal work day. As you are grabbing your coffee in the kitchen, you start hearing some murmurs in the background. On your walk back to your desk, the murmurs grow louder and louder and suddenly end in silence. You rush back to your desk and as soon as you turn on your laptop… the whole office erupts in chaos! The cause of the chaos? The office network has gone dark. So no emails, no Slack, no video calls, no access to shared folders.

While this “imaginary” scenario may sound a little exaggerated, it isn’t far from the truth. Without access to the network and the Internet, everyone is severely hamstrung and unable to perform almost any of their tasks. Since most if not all of our workloads and tools are in the cloud, there isn’t a whole lot of work we can do in the office without Internet access.

Unfortunately, device, infrastructure, and system failures resulting in network outages are not uncommon. So network outages are more than likely to occur at your organizations. Thankfully, network infrastructure can be designed to effectively handle such situations.

This quality of networks that enables them to handle disruptions and recover quickly from outages is called network resilience and that’s what we will discuss in this blog post.

What is Network Resilience?

Network resilience is the ability of a computer network to cope with disruptions, failures, or attacks while continuing to provide communication and services to its users at an acceptable standard. A resilient network responds to, adapts, and recovers from disruptions, including cyber threats, failed devices, natural disasters, etc.

While all networks are able to recover from disruptions, less resilient networks are not well-equipped to face disruptions, resulting in frequent or longer downtimes. On the other hand, highly resilient networks are able to respond to adverse conditions and recover quickly, enabling business operations to continue without interruption.

What Is The Importance Of Network Resilience?

Network resilience is critical for every modern organization that relies on networked systems and services. Network outages lead to downtimes and service disruptions that businesses can ill afford. Every hour of downtime costs businesses hundreds of thousands of dollars in lost revenue, loss of productivity, opportunity costs, and loss of reputation.

Additionally, customer expectations are also increasing. It is therefore common for businesses to compete on availability and SLA offerings, which requires network operations to be up as close to 100% of the time as possible. To meet such elevated standards organizations need to build network infrastructure that is highly resilient.

How Can You Achieve Network Resilience?

The following are the key elements that help make the network resilient:

• Fault Tolerance

Fault tolerance is the ability of a network to continue operating without interruption when one or more of its components fail. Fault tolerance won’t necessarily maintain the network at full functionality but will allow the network to continue operating with limited functionality so as to ensure the high availability and business continuity of mission-critical applications or systems.

Fault tolerance is typically achieved by using backup components, which automatically take the place of failed components, to ensure that there is no loss of service. An example of fault tolerance is commonly found in servers where multiple hard drives are configured in a RAID (Redundant Array of Independent Disks) configuration. This ensures that even if one hard drive fails, data is not lost, and the server can continue to operate.

• Redundancy

Redundancy is the duplication of critical components or systems, which serve as a backup or fail-safe, in a network to increase the reliability of the network. A redundant network setup focuses on having backup components, paths, or services in place to effectively handle failures by providing alternative routes or resources to maintain network operations in the face of disruptions.

A common example of redundancy is the use of two internet service providers (ISPs). If one ISP experiences an outage, traffic can automatically failover to the other ISP. This way Internet availability can be maintained in the network without any downtime.

Redundancy vs Fault Tolerance

Redundancy and fault tolerance are similar concepts and are often used interchangeably. However, they are not the same. While the goal of fault tolerance is to prevent or mitigate failures within individual components, the goal of redundancy is to provide backup systems or paths to maintain operations in the event of a failure. Nevertheless, both approaches contribute to network reliability and uptime albeit by addressing different aspects of resilience within a network.

• Load Balancing

Load balancing is a method of distributing network traffic across multiple servers, paths, or resources so that no single point is overloaded. Load balancers function like manifolds distributing client demands across all network resources that can fulfill them. Distributing network traffic evenly reduces the risk of network congestion or failure due to heavy loads. Additionally, it can also help improve resource availability and responsiveness, and maximize speed and capacity utilization.

• Security

The first thing necessary for the uninterrupted availability of network resources is to ensure network integrity. This means protecting the network against cyberattacks, data breaches, and unauthorized access. So, robust network security is essential for network resilience.

• Monitoring And Management

The early detection of anomalies and vulnerabilities is essential for network health and performance. Therefore, continuous monitoring of the network using effective network management tools and practices is an essential part of a resilient network.

• Scalability

A resilient network must also be able to accommodate growth without performance degradation. So it should be able to scale up or down in response to changes in demand or traffic patterns with minimal impact on network performance.

• Disaster Recovery

A disaster recovery plan outlines the process of regaining access to and functionality of critical operations, services, and systems in the event of natural disasters, hardware failures, or other catastrophic events. And when it comes to critical services, network services typically figure at the top of the list.

• Adaptive Routing

Adaptive routing, also called dynamic routing, is a technology that dynamically adjusts the network's routing paths in response to changing conditions, such as link failures or congestion, to optimize traffic flow. Adaptive routing aids network resilience by enhancing network performance, preventing packet delivery failure, and controlling network congestion.

• Testing and Simulation

Regular testing and simulations help assess the network's resilience, identify vulnerabilities, and prioritize network traffic to ensure critical applications and services receive the necessary bandwidth, even under adverse conditions.

• Documentation and Training

A couple of key and often overlooked elements necessary for building network resilience are documentation and training. These play a critical role in helping network administrators to effectively respond to network incidents and maintain resilience. They also empower network administrators to act quickly and decisively in the event of catastrophic events. Thorough documentation and regular training are therefore absolutely essential for maintaining a resilient network.

Are Network Resilience And Network Redundancy The Same?

Network resilience and network redundancy are related but the two are not synonymous. As we mentioned earlier, redundancy is a key element of network resilience. A redundant network includes backups of key components such as routers and firewalls. This ensures that if one of the network components fails, the traffic is routed through the secondary component and the network will keep functioning.

Network resilience, on the other hand, involves a variety of steps aimed at ensuring network health, high availability, performance, and security. Network resilience requires a lot more than backup components, it requires systems, processes, planning, and training so that the network infrastructure is able to support business continuity goals.

Additionally, modern business networks are highly complex consisting of a large number of components and applications. These components and applications frequently run into issues, small and big. Having redundancies for all of them is not only expensive but also very difficult. So, network resilience focuses on restoring network operations, reducing the time for fault identification and resolution, rather than outright replacing the entire network.

Network Resilience Checklist

Here’s a network resilience checklist to help you get started with assessing and improving the resilience of your network infrastructure.

1. Fault Tolerance

• Are critical network components (e.g., switches, routers, firewalls) equipped with redundant power supplies and network interfaces?

• Is RAID (Redundant Array of Independent Disks) or a similar technology implemented for critical storage systems to prevent data loss in case of disk failure?

• Do you have backup generators and uninterruptible power supplies (UPS) in place to ensure continuous power in the event of electrical grid failures?

• Do you have a disaster recovery plan outlining procedures for recovering from catastrophic hardware failures or natural disasters?

2. Redundancy

• Do you have a secondary internet service providers (ISPs) to ensure internet connectivity in case your primary ISP suffers an outage?

• Is dynamic routing configured to automatically reroute traffic in the event of a router or link failure?

• Do you use load balancers to distribute traffic across multiple servers, providing redundancy for web applications?

• Do you use redundant data centers or cloud regions to ensure business continuity and data availability?

• Do you have a backup and restore strategy for network device configurations and data?

3. Security

• Does your network have firewalls, intrusion detection systems (IDS), and intrusion prevention systems (IPS) in place to protect against cyberattacks?

• Do you use encryption (e.g., SSL/TLS) to secure data in transit?

• Do you regularly perform security assessments, penetration tests, and vulnerability scans to identify and address potential security vulnerabilities?

• Do you enforce access controls and authentication mechanisms to prevent unauthorized access to your network?

• Do you monitor network traffic for anomalies and security breaches?

4. Monitoring and Management

• Do you have a centralized network monitoring system to track network performance and detect anomalies?

• Do you keep all network devices and software up to date with the latest security patches and firmware updates?

• Have you implemented traffic shaping and quality of service (QoS) mechanisms to ensure critical applications receive priority during congestion?

• Do you maintain backup copies of network configurations, device settings, and documentation in case of accidental changes or data loss?

• Do you have procedures in place for quickly isolating and mitigating network incidents and security breaches?

5. Disaster Recovery and Business Continuity

• Do you have a documented disaster recovery plan that includes backup and recovery procedures for network resources and data?

• Do you have offsite backups and data replication strategies in place to ensure data availability in case of loss of location or site-wide failures?

• Do you conduct simulations to test the effectiveness of disaster recovery and business continuity plans?

• Have you assigned and informed key personnel of their roles and responsibilities in the event of a network-related crisis?

6. Documentation and Training

• Do you have comprehensive documentation for network configurations, topologies, and procedures?

• Do network administrators and operators regularly receive training on security best practices and incident response procedures?

• Do you have a clear escalation path and communication plan for notifying stakeholders in the event of network incidents or outages?

• Do you keep network diagrams and inventories up to date to reflect the current network infrastructure?

Note that the checklist shared above is a generic one to help you get started quickly. You will, however, need to customize it to align with your organization's specific network architecture, policies, and requirements. Additionally, remember to regularly review and update the checklist to ensure that your network remains resilient in the face of the evolving technology environment and threat landscape.

Conclusion

Network operations and services are under a wide range of threats including cyberattacks, misconfigurations and errors, power outages, and natural disasters. Unfortunately, such eventualities occur more often than we think. And when they do happen, organizations suffer loss of productivity in simple cases but in more severe cases they can suffer from loss of revenue and loss of reputation. Thankfully, highly resilient networks can prevent this from happening by preventing network outages or restoring network operations quickly.

How resilient is your network? Do you have all safeguards including fault tolerance, redundancy, and security in place? If you are not sure, reach out to us by clicking the button below and learn how we can help improve and maintain your network resilience.

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