Network segmentation works by adding barriers to an organization’s network, thereby regulating the traffic that goes in and out of each segmented zone. With security protocols implemented for each component, organizations are able to limit the potential for unauthorized access to highly-sensitive and business-critical data. Properly configured segments can limit who can access them, and how they can be used by each user.
With rising threats to cybersecurity, measures like network segmentation are an organizational necessity. The cost of cybersecurity is expected to exceed $10.5 trillion by the year 2025 as businesses continue to look for solutions that prioritize security without compromising business functions. Network segmentation offers that opportunity as a viable security protocol. Different organizations may be better suited for different types of segmentation to keep their network secure. These types include the following.
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Physical Segmentation
Physical network segmentation divides the larger network into smaller components with the use of physical hardware, as opposed to software used in logical segmentation. Then, like any other type of network segmentation, the traffic entering and leaving each subnet is tightly regulated, with access limited to authorized individuals. With this technique, highly-sensitive information can be kept on an entirely independent segment of the network that cannot be accessed via the less secure network components.
The hardware involved in physical segmentation includes switches and routers, that divide up the network using physical firewalls. This gateway then determines what traffic is to be allowed to enter or leave, based on pre-defined principles. These security protocols can also limit user functions on the network, to ensure no user is able to access data that is not strictly required for the purpose of their use. With a simple and straightforward architecture, physical segmentation can be easy enough to manage.
Benefits and Drawbacks of Physical Segmentation
With physical segmentation, dedicated hardware is used to create segments in the organization’s network. This makes it one of the most secure segmentation options, as the hardware cannot be virtually disrupted or broken by malicious attacks. In the unlikely event that one or more segments of the network are attacked, the segmentation policy contains the attack and is more likely to stop it before it can attack highly-sensitive data.
Similarly, in case an attack is imminent, it gives the organization more time to implement further defenses against it. With physical network segmentation, an attack is likely to begin with the least secure segments, giving you time to secure the higher-sensitivity segments.
On the other hand, physical segmentation can be hard to maintain and manage, as the dedicated hardware requires its own external setup, such as an independent internet connection that is not accessible by other employees or patrons. The least trust principle that this type of segmentation provides is based on distrust for external sources, but not internal, meaning the organization remains vulnerable to an internal attack.
VLAN segmentation
Most network segmentation solutions use Virtual Local Area Networks (VLANs) to create smaller networks that all connect to the same domain. Unlike in physical segmentation, where each subnetwork is independently connected, VLAN segmentation does not physically separate the network components. They remain in the same location, connected to the same larger network, allowing multiple subnets to function and operate semi-independently under the network umbrella.
VLAN segmentation works by only allowing the users under the same VLAN to be able to communicate with each other- external communication with networks outside the VLAN is restricted. Once VLAN segmentation is applied, different protocols can be implemented for each of the different segmented VLAN networks, based on the degree of access allowed for each. Each VLAN subnet in the network uses a separate IP address, and cross-communication between subnets requires the use of a router.
Benefits and Drawbacks of VLAN Segmentation
VLAN segmentation has a decided advantage over physical segmentation in that it removes the geographical constraints found in the latter. LANs require connected devices on a single network to be in a single, limited geographical location in order to connect to the network and communicate with each other. VLAN circumvents this necessity, allowing remote access, while still maintaining security protocols.
However, VLANs do have some hardware requirements, such as a router to enable inter-communication. In this case, it is possible to tap into a less secure subnet and use it to transfer malicious data packets to other VLANs. As such, it does not ensure complete security from unauthorized access or attacks. While VLAN can be secure, and ensures business functionality, it may require additional security protocols to limit threat risk.
Software-defined network (SDN) segmentation
Software-defined network (SDN) segmentation is a type of micro-segmentation that is entirely based on the use of software tools to segment and manage networks, unlike physical and VLAN segmentation, that use hardware devices. Micro-segmentation allows the organization network to be broken down into logical segments, and each segment is assigned well-defined security protocols that dictate how that subnet is used and who can access it.
SDNs will typically use software like an application programming interface (API). It also lets organizations make changes as their network architecture grows and evolves. API SDN controls the flow of traffic between devices and thus enables real-time changes to be implemented as needed. The entire network is configured in a single centralized location, from which traffic flow is automated and monitored. This also includes the implementation of virtual firewalls that prevent unauthorized access.
Benefits and Drawbacks of SDN Segmentation
SDN segmentation has the decided advantage of improving network security through simplistic software controls. It does not require hardware investments and can be managed through automated processes and traffic flow configurations. While it is considered extremely secure, it does also have some limitations.
While centralized network control is simple, it also acts as a single failure point- if malicious agents gain access to this point, they can topple the entire network. Organizations may have to invest more to ensure the security of the centralized controller to keep the entire organizational network safe.
Final thoughts
Network segmentation offers a viable security measure against the rising threat of cyberattacks. By isolating network segments, organizations can ensure that any possible attacks are immediately contained, and can be handled without losing sensitive data. As such, depending on an organization’s needs, physical, VLAN, and SDN segmentation all may work well.
Organizations that are able to invest in hardware to secure the network and don’t require remote access may work better with physical segmentation. Similar organizations that also need to enable remote authorized access should opt for VLAN segmentation. Entirely software-based organizations can best secure their network with SDN segmentation, cutting out hardware costs.