As networks become larger and more complex, managing them is becoming a nightmare for network administrators. To stay on top of the health and security of networks and monitor the flow of traffic through them, it's important to use multiple strategies including network segmentation.
Read on as we talk about network segmentation, its types, and how to best implement it in your network for modern-day cybersecurity.
What is Network Segmentation?
Network segmentation is a security strategy where you divide a network into smaller segments or subnetworks. This division enables you to have better control over the operations of the subnets and the flow of data between subnets. Also, network segmentation limits access to sensitive data, devices, and applications, thereby reducing the attack surface and improving security posture. Another advantage is that network segmentation improves network performance and simplifies overall network management.
Benefits of Network Segmentation
Here's a detailed look at why you must segment your network.
- Enhanced security Network segmentation makes it easy to implement security policies. Many organizations are moving towards zero-trust and least-privilege access management. Zero trust means that an individual or device must prove that it is authorized to access a resource, usually in the form of a password or authentication code. Likewise, least privilege access means that only those individuals or devices that need a resource must be given access to it. Network segmentation makes it easy to implement such security measures because it can be implemented in chunks within each subnet.
- Improved Network Performance Network segmentation makes it easy for you to stay on top of the health and performance of your organization. While it's impossible to monitor every device on the network, it's easier to monitor multiple subnets and the flow of traffic across subnets. This information helps you to identify the bottlenecks in network performance and fix them at the earliest. In this sense, network segmentation helps with both identifying the root cause and troubleshooting it.
- Simplified Network Management Another huge advantage of network segmentation is its simplified management. You can easily manage multiple subnets over one large complex network. Let's understand this benefit with a simple example. Let's say, you want to add a new device. If you haven't segmented your network, you will have to update every device on the network to include a pathway to the new device. However, in a segmented network, the number of devices that you must update will be fewer, saving you time and effort.
- Compliance Compliance is an underrated benefit of network segmentation. Many standards like PCI DSS require you to implement stringent security controls in your network. Network segmentation makes it easy to implement these controls across smaller groups instead of one large group. More importantly, you can stay on top of the changing compliance requirements and implement them quickly to those subnets that are in scope.
From this discussion, there's no doubt that network segmentation can have a far-reaching impact on your network's performance and security. Next, we'll talk about the types of network segmentation. Using this information, you can decide which type works best for you, and how you can implement it in your network.
Types of Network Segmentation
There are two types of network segmentation: physical and logical. Let's take a detailed look at both these types of network segmentation.
- Physical Segmentation As the name suggests, physical segmentation is where you physically move the devices into different subnets. Typically, physical segmentation involves using hardware like routers and switches to divide the devices. A firewall acts as the gateway for each subnet to control the inflow and outflow of traffic. Physical segmentation is simple to implement as the topology is linked to the network's underlying architecture. Most physical segmentation involves the use of routers to separate devices into subnets. However, there is another type called the air gap, where the devices are pooled into separate subnets in such a way that there's no common connection between them. This is an extreme implementation and is often used to isolate sensitive data from any device that can connect to the Internet.
- Logical Segmentation Virtual or logical segmentation, on the other hand, is about logically separating devices into multiple subnets. This is commonly implemented using a Virtual Local Area Network (VLAN), and sometimes through network addressing schemes. The choice depends on the organizational network and resource availability.
Out of the two, VLANs are easier to approach because you can use software to route traffic to the appropriate subnet. Though network addressing schemes also use software to segment devices logically, it requires an in-depth understanding of network topology and architecture. In other words, a network addressing scheme requires the presence of experienced experts.
Now, you may wonder if you should opt for physical or logical segmentation.
Physical vs Logical Network Segmentation
| Feature | Physical Network Segmentation | Logical Network Segmentation |
|---|---|---|
| Implemented by | Hardware like routers and switches | Software |
| Cost | Requires the creation of new subnets and hardware. Hence, more capital-intensive | Builds on the existing infrastructure, though a software is still needed for segmentation. Less expensive than physical segmentation |
| Flexibility | Low | High |
| Resource usage | High and often wasteful and inefficient. For example, not all the ports in a router may be used in physical segmentation | Highly efficient, as the devices are separated logically. With some planning, resource utilization can be optimal |
| Ideal for | Small networks | Large and complex networks |
| Types of implementation | Air gap and use of routers | VLANs and network addressing schemes |
In all, logical segmentation using VLANs is by far the most popular way to segment a network because of its many benefits. That said, the choice depends on the size of your network and the benefits you're trying to achieve with this process.
Regardless of which network segmentation method, make sure to use some best practices for getting the most out of it.
The Best Practices for Implementing Network Segmentation
The best practices, mentioned below, can help you to leverage segmentation to gain multiple benefits.
- Create Security Policies As a first step, make sure to create the security policies that define your segmentation process. Remember, these policies must help you reach the goals you want to achieve through segmentation. While formulating these policies, consider the type of data and the kind of resources in your network, how they are used, who are the players, and more. Based on these different aspects, formulate the appropriate security policies for implementing network segmentation.
- Have Access Controls in Place Access controls are a key strategy to streamline security and access to the resources in your organization. Consider using a zero-trust policy where a device/individual has to authenticate themselves to access a resource. This can also give you better control over who accesses your resources and when.
- Automation Consider using automation to maintain your network security. You can implement automation at various levels in your network and operations to streamline security. A good example of automation is a device locator that will help you identify the location of a device and how it's connected to your network. This information can save you a ton of time while troubleshooting or checking the availability of the device. Likewise, network configuration check tools like the SolarWinds Network Configuration Manager can come in handy to identify changes in configuration. Also, you can use its configuration templates to quickly set up devices and connections.
Leveraging the above tools and practices can go a long way in reaching your network and security goals through network segmentation.
Before we end, let's take a quick look at the challenges that come with network segmentation, so you can be on the lookout for them.
Challenges of Network Segmentation
Though network segmentation offers many benefits such as the ones we discussed earlier, it also comes with its share of challenges. Knowing these challenges can help you to plan ahead to avoid them.
- Complexity Implementing network segmentation is a complex process, especially if your organization has a large network. You will have to design a comprehensive segmentation plan, procure the compatible hardware or software based on the type of implementation, and execute the plan. All of these are time-consuming and effort-intensive.
- Cost Network segmentation can be expensive. In general, physical segmentation can be more expensive than logical segmentation because of the additional hardware required. At the same time, logical segmentation also requires software, which may not be as expensive as hardware but will still cost money. Also, you need experts to implement the network segmentation, and this can add to your costs.
- Maintenance Network segmentation requires constant monitoring and maintenance, as you may have to move devices and resources to meet new changes. Also, you may have to update the segmentation based on emerging security threats, compliance requirements, and more.
- Addressing the Challenges You can address these challenges in many ways. To tackle the problem of complexity, start with a clear goal and a time frame. Take a phased approach and prioritize those segments that are more critical and important for your organization. You can use network security and configuration tools like SolarWinds Security Event Manager or Network Configuration Manager to automate some of the tasks.
To bring down the cost, consider using open-source software over proprietary ones. Also, create physical segmentation as efficiently as possible to reduce the number of routers and switches needed. Finally, you can ease the maintenance process with well-defined security policies that don't require changes often. Also, using automated tools can bring down the time and effort needed.
Conclusion
Network segmentation is a powerful security strategy to have better control over your network's health and performance. This strategy offers many benefits like controlled access to sensitive data, improved visibility into your network's traffic, ease of maintenance, and more. However, implementing network segmentation can present some challenges, in the form of complexity, cost, and maintenance. To address these challenges, organizations should take a phased approach, prioritize segments based on their sensitivity and criticality, use network security tools, and establish clear policies and procedures for managing and monitoring segmented networks.
With careful planning and execution, network segmentation can be a powerful tool for improving your organization's security posture and protecting your digital assets. With proper choice and implementation, you can also reduce the risk of data breaches, minimize the impact of security incidents, and ensure business continuity.
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