NordLayer - Network Security

Micro-segmentation: everything you need to know

By NordLayer
5 Apr 2022
9 min read
Micro segmentation. Everything you need to know

Maintaining firewall integrity and proper network security policies across all data servers can be time-consuming and hard to manage. But with a micro-segmentation strategy, networks can be broken down into multiple segments and secured against potential cyberattacks. This blog explains what micro-segmentation is, how it works, and how it could help your business thrive.

What is micro-segmentation?

Micro-segmentation is a development of traditional network segmentation which mitigates many of the flaws associated with older methods, adding finer granularity and more robust east-west protection.

Network segmentation has been around for decades. It divides networks into smaller sections like VLANs or “subnets” and enables managers to oversee information flows and user behavior, preventing unauthorized access to sensitive resources. Without segmentation, any user accessing a network would be free to roam between servers and applications, creating a massive security risk.

Micro-segmentation is superficially similar to traditional segmentation strategies but with some significant differences. Traditional methods rely on perimeter-focused security tools like subnets and firewalls to construct barriers between resources. Micro-segmentation solutions employ Software Defined Network controllers (SDNs) or other tools at a workload level.

In micro-segmented networks, managers enjoy far higher control over how resources are accessed. Applications and devices can be managed at a granular level, ensuring that only users with specific privileges have access. As with older forms of segmentation, micro-segmentation controls north-south traffic via perimeter defenses like firewalls. Unlike older methods, east-west traffic is also rigidly controlled. With a solid micro-segmentation solution, companies can create secure zones to lock down every device or app.

While standard network segmentation creates secure VLAN and subnets, micro-segmentation can achieve the same protection at the virtual machine or host level. It allows managers to tightly police lateral movement within networks, while attackers will find it harder to roam freely and access sensitive data. These factors make micro-segmentation a fundamental building block of Zero Trust Network Access (ZTNA) systems, allowing managers to manage access control in ways that older segmentation strategies cannot deliver.

What are the essential types of micro-segmentation

There are three main types of network micro-segmentation, and each one has a crucial role in the world of cyber-security.

Network micro-segmentation

Also known as infrastructure segmentation, this micro-segmentation form is the most similar to older forms of network segmentation. It usually divides data center resources into Virtual Local Area Networks (VLANs) and uses Access Control Lists (ACLs) or IP constructs to determine user access.

Standard network micro-segmentation is not generally a fine-grained solution, as it applies at the VLAN level. However, network micro-segmentation is familiar and easy to use. On the other hand, this method can lead to significant security gaps and sub-optimal east-west traffic control.

If managers seek to increase their network visibility and control, ACL or IP constructs can become extremely expensive and unwieldy, resulting in network bottlenecks. These drawbacks have led to alternative micro-segmentation options that balance control, speed, and cost.

Hypervisor micro-segmentation

All data flows through a hypervisor in this setup, which creates a virtualized security environment and overlays network security architecture. Virtual machines emulate Software Defined Networks and tend to offer an excellent segmentation solution for networks dependent upon VMware infrastructure.

However, this approach is not suited to networks dependent on Cloud services and does not work well with bare metal systems either. So it’s a niche solution, but one that can be very effective in VMware environments.

Host Agent micro-segmentation

This configuration locates Software Defined Networking agents in network endpoints and hosts. These agents deliver feedback to centralized management tools, provide access control at a device level, and allow managers to monitor data flows across the network.

Network managers can install agents in bare metal, hybrid, or Cloud settings, and each host will require an agent to ensure complete protection. Managers can set access privileges for different roles when this agent is in place, segmenting networks as they see fit.

The proliferation of host agents can make host agent segmentation a complex solution, and it can lead to network throttling as device numbers grow. Managers must also ensure that agents are updated as systems evolve. However, host agents are a convenient option when remote working devices are involved and can combine easily with existing security tools on those devices.

How does micro-segmentation work?

As we’ve seen, there is no single form of micro-segmentation, but the different varieties tend to function in similar ways.

Most hypervisor or host-based solutions rely on Software Defined Networking controllers. These controllers reside on the primary data center but create secure segments to distribute throughout the entire network.

SDNs create a virtual network or overlay, emulating physical networks and disseminating security policies to every endpoint, device, and application. Tunneling protocols allow secure connections between hosts and the data center within a virtualized environment.

Access control to data center resources is managed via multi-factor authentication, while individualized security policies determine user freedom within the network. If users breach those security policies, managers will know instantly.

Micro-segmentation takes place at the workload level. Security reams can contain any security breaches easily and rapidly, limiting any potential damage. It also means that managers can secure remote workstations and data centers alike – a key consideration as home working expands.

The software-based nature of micro-segmentation enables security managers to adjust controls to reflect changing network architecture. They can add extra devices or lockdown Cloud resources as they are installed, providing total flexibility and edge protection. There is generally no need for hardware-based firewalls, and the security perimeter can expand or contract when needed.

Micro-segmentation: Benefits and challenges

Micro-segmentation is a viable and valuable security strategy for many businesses, but it won’t always be the correct option. As with all security technology, it comes with costs and benefits, and these need to be taken into account when planning a macro or micro-segmentation implementation.

Benefits of micro-segmentation

  • More robust east-west network traffic control – Micro-segmentation controls movement within network perimeters in ways that older VLAN-based systems cannot. SDNs (or even ACLs) can police the resources available to specific users. Managers can assign privileges to roles or groups, and attackers will find it very hard to move laterally from weak endpoints to sensitive databanks.

  • Breach containment: When attackers access internal networks, they will find it more challenging to reach sensitive resources. Managers will be able to locate, isolate, and contain malevolent agents as soon as they breach security protocols.

  • Smaller attack surface: Micro-segmentation keeps threat surfaces as small as possible, reducing the chance of a successful cyber-attack. Software agents located within data centers and distributed to every endpoint represent an efficient alternative to the firewall and VLAN-based options.

  • Flexibility: Software-based segmentation is ideally suited to organizations dependent upon remote working and Cloud environments. Whether you choose hypervisor or host-based segmentation, networks can be scaled up or reshaped without compromising internal security.

  • Regulatory Compliance: As data breaches increase in size, cost and frequency, cybersecurity regulatory compliance becomes a significant issue. Granular segmentation could be a good risk management option, whether you seek to comply with HIPAA, ISO, or PCI-DSS standards.

Potential costs of micro-segmentation

  • Compatibility issues: Some applications can present compatibility issues when implementing micro-segmentation, leading to compromised performance, expensive procurement and retraining, and unplanned downtime. Security teams can often mitigate this at the planning stage, but some systems will not be suitable and require alternative strategies.

  • Extra workloads – Every user and device will require a specific security policy, and organizations will need to establish controls on an individual basis. Creating these micro-segmentation policies can be time-consuming, and it can also lead to disputes about the level of permissions granted to departments or roles. Some workers may find themselves locked out of essential resources as a result.

Which businesses need to segment their networks?

Companies can apply micro-segmentation in many different settings and ways, but it isn’t suitable for all business environments. In some cases, traditional segmentation may be preferable, while other networks may not require segmentation.

Generally speaking, micro-segmentation will be an effective security option for businesses with large numbers of remote working devices and reliance on Cloud resources or centralized data centers.

Remote or hybrid working is now becoming routine for corporations around the world. Around 60% of those who can work from home do so in the USA alone. And when workers leave office settings, endpoint security becomes essential. SDN-based segmentation can ensure that remote workers only have access to resources that match their roles while helping to contain any breaches via poorly secured remote workstations.

Micro-segmentation is also advisable for companies in highly regulated fields where compliance is a core concern. For instance, health care companies regulated by HIPAA standards could segment customer data from marketing, accounts, and research departments.

In a broader sense, micro-segmentation is well-adapted to any business seeking to implement a Zero Trust Security Model based on the principle of least privilege. SDN-based segmentation is ideal if you need to design in-depth access lists for roles or individuals and want total awareness of user activity.

However, applying micro-segmentation across large organizations can be costly, especially when handling extensive low-sensitivity network traffic. And smaller organizations with less budget to invest in sophisticated software-based segmentation may still achieve strong perimeter defense via traditional methods.

How to implement micro-segmentation

Several factors come into play when adopting a micro-segmentation approach, both before and after the necessary infrastructure has been installed.

  1. Firstly, decide which network resources have a high sensitivity and require the highest degree of protection. It may be helpful to refer to compliance regulations at this stage to ensure that critical databases or apps enjoy enhanced security.

  2. Identify essential apps and devices on your network that require enhanced protection. Try to map out remote working endpoints and create a set of security protocols to define the level of access for every user.

  3. Use the information gathered to create detailed maps and tables showing the fundamental composition of your network. Map out which areas need to be segmented and create clear labels to ensure that the system is intelligible for all who use and manage it.

  4. Avoid a “one size fits all” approach when crafting micro-segmentation setups. Take care to investigate the specific vulnerabilities of each device or process and the needs of the people that use them.

  5. Commission a suitable set of software-based security tools to implement a segmentation approach that meets your needs. The optimal setup could involve SDN controllers, hypervisor, or hybrid software and hardware-based protections.

  6. Create protocols to monitor security performance, control network traffic flows, and schedule regular audits. Ensure that threat reporting processes are clear and comprehensive, along with threat containment and mitigation strategies.

Partner with NordLayer to implement micro-segmentation strategies

As you’ve probably ascertained, there is no single micro-segmentation solution. Companies need to find a comprehensive security strategy that matches their threat environment, working practices, and budget. At NordLayer, we can work with security teams to find tailored network segmentation solutions that fit every situation.

Our security services include micro-segmentation tools to deliver unprecedented granularity and control. Lock down essential apps and client databases, make remote work ultra-safe while ensuring user-friendly access, and guarantee rock-solid compliance.

Get in touch with the NordLayer team, and we’ll discuss approaches to make micro-segmentation work for you.

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