Network Segmentation

In an era where cyber attacks can take a profound toll on organizations of all sizes, your company needs a multi-layer cybersecurity architecture. One of its most important aspects is the hardware firewall that regulates the flow of all traffic coming into and exiting your network. There are several ways that you can configure this perimeter security service to meet your unique needs, and one of the most powerful is known as network segmentation. Because implementing this security strategy is no easy task and the model is not ideal for all businesses, it makes sense to learn if this method will improve your infrastructure and be worth the investment of resources that it requires.

Network Segmentation Security Defined

As the name suggests, this practice involves dividing a network into several smaller zones known as subnets whose data has similar compliance requirements. Each of these subnets functions as its own small network, and it is possible to control or totally block the flow of traffic among them based on rules and stipulations that are set up in advance.

Benefits of Segmentation in Network

Thanks to a network segmentation design, productivity and efficiency are boosted because data only goes where it is needed. As a result, your computer networks and other resources can be protected in a more robust and efficient way. Benefits include the following:

  • Hampers attackers. If a threat actor breaches your firewall and gains access to your servers and applications, time is of the essence. When your large network environment is broken up into smaller ones, navigation becomes more challenging for a cyber criminal looking to gain access to your sensitive information. During those precious minutes or hours, your internal threat detection, isolation and neutralization cybersecurity tools can limit the breach, hopefully before serious damage has been done.
  • Provides enhanced security. A segmented network is particularly beneficial when it comes to your most sensitive caches of data. The more you are able to control and contain traffic and limit what flows to your critical assets, the easier it is to secure and protect them.
  • Enables you to limit user permissions. This is known as the Policy of Least Privilege in which access to applications, services, programs, accounts and systems is given only to those who absolutely need it. Segmentation gives you a way to protect data in the event that a user’s credentials are compromised from the outside or abused from within your business.
  • Limits the scope of an attack. By restricting the impact to a small number of workstations, segmentation helps to minimize the impacts of an external breach or the fallout from internal human error.

Segmentation can also provide increased protection against any vulnerabilities that could infect your data center or network stemming from a third-party vendor. 

All in all, putting this configuration into place furnishes segregation of traffic flows that helps to keep your entire cyber environment safer. Although setting it up can be time- and labor-intensive, network segmentation minimizes the likelihood that threats will turn into a full-scale intrusion.

Network Segmentation Best Practices

A strong network security structure should contain several parts. For one thing, it is essential that your design features an internal zone that is highly protected against breach and never directly accesses the internet. This zone contains workstations, internal servers, non-internet facing databases, active directory services and internal networks. You will also need an external untrusted network zone. 

Finally, many configurations include a framework of intermediate security zones that group similar systems and servers together in a Layer3 subnet. The network segmentation strategy works by controlling the traffic flows among the various servers and zones at all levels, including IP, port and application.

Depending on your company’s functionalities and requirements, you will need to determine how to segment a network optimally to suit your needs. However, keep in mind that the servers in your Layer3 DMZ subnet may have to be internet-facing. Examples include email and web servers that bring in data from outside. In these situations, you should separate them from other less vulnerable applications.

Best practices also pertain to the regulation of traffic flow. Your segmented firewall product should be configured such that it only accepts traffic from specific ports such as 25 and 80,443, etc. In addition, all other TCP-UDP ports should be closed.

Another best practice relates to the segregation of servers. In general, database servers should not be in the same zone as web servers; front end and web application servers should also be kept distinct from each other.

Even the most robust network segmentation methods are only a small part of the full suite of products, services and human expertise that you will need to assemble to increase your cybersecurity posture. Additional advice in this respect includes utilizing a cloud-based web filtering application that can help you to enforce your security policies with staff. This solution works by preventing end users from going to websites known to contain malware or that go against your established usage protocols.

Improved security is an ongoing battle. With threat actors constantly evolving in their techniques and strategies, it is essential that your IT team and third-party vendors use every resource and tool at your disposal to protect your valuable assets. Network segmentation may well be one of your most effective investments.