What is Network Segmentation? Virtual & Physical Segmentation
Network segmentation or segregation is a network architecture practice used by network security personnel to divide an organization’s computer network into smaller subnets. Each subnet or network segment forms its own smaller network.
By segmenting an organization’s network, personnel can better control the traffic flow between subnets, improve security policies, and make it more challenging for unauthorized users to access sensitive data and critical parts of the network.
Keep reading to learn more about the benefits of network segmentation, discover the difference between virtual and physical segmentation, and why the practice is essential for cybersecurity programs.
Micro-segmentation vs. Network Segmentation
Network segmentation and micro-segmentation are key strategies security personnel should implement to improve network security. The main difference between network and micro-segmentation is that network segmentation limits north-south traffic (in and out of a network), while micro-segmentation is focused on securing east-west traffic (internal network traffic).
In most instances, network segmentation is the overall security policy an organization employs to protect its network infrastructure. Micro-segmentation, on the other hand, is a more nuanced strategy utilized to protect intra-network traffic. Micro-segmentation involves restricting access to devices, servers, and apps that communicate directly with each other.
What are the Benefits of Network Segmentation?
Network segmentation offers organizations and network security teams a variety of benefits. The main advantages of network segmentation include:
- Stronger Network Security
- Decreased Congestion, Improved Performance
- Threat Containment
- Improved Monitoring
- Endpoint Device Protection
Stronger Network Security
The most obvious benefit of network segmentation is improved network security. An organization can isolate network traffic, contain lateral movement, and minimize its digital attack surface by splitting its network into smaller subnetworks.
Decreased Congestion, Improved Performance
Another primary benefit of network segmentation is decreased network congestion. When too many users connect to a network, the network’s performance may suffer significantly, primarily when users transmit data simultaneously. An organization can relieve congestion and boost network performance by subnetting its network.
Network segmentation can also help organizations improve their threat containment strategies and isolate network attacks before they spread.
For example, if a malware infection infects a network, the attack could spread quickly into all areas of the network. However, when a malware infection affects a segmented network, it can only extend as far as the segment will allow. Therefore, one subnetwork may be affected by the malware attack, but the rest of the network system would not be infected.
Network segmentation allows organizations to install more checkpoints for network monitoring. By installing these checkpoints, network personnel can better intercept suspicious activity before cybercriminals carry out a cyber attack. In addition, by learning how attackers behave, personnel can develop proactive strategies to improve network security and protect high-risk areas of their organization’s network.
Endpoint Device Protection
Another benefit of network segmentation is increased endpoint device protection. Endpoint devices (physical devices that connect to a network) are a common target for cybercriminals or hackers because they often lack stringent security protections.
By controlling the flow of traffic, network segmentation prevents malicious traffic from compromising unprotected devices. This benefit will continue to become increasingly important as Internet of Things IoT devices and public cloud security principles become increasingly common in the workplace.
How Does Network Segmentation Work?
In simple terms, network segmentation divides one flat network into multiple isolated segments. Organizations can then employ varying security strategies and access control lists to govern each of these smaller networks. Specific segments can require different applications or endpoint types with varying trust levels.
There are two main types of network segmentation:
- Physical Segmentation
- Virtual Segmentation
Physical network segmentation utilizes routers, wiring, connections, switches, firewalls, and other hardware to divide an organization’s network into segments. Physical segmentation is generally simple to manage, given that security personnel can access all physical architecture in the same place.
Virtual or software-defined network (SDN) segmentation uses software to create network segments or partitions. Most network security personnel prefer virtual network segmentation techniques because they typically don’t require new hardware. Instead, virtual segmentation utilizes automation to build upon an organization’s infrastructure.
Organizations that adopt virtual segmentation can simplify their firewall management programs and create a comprehensive security policy that includes rules and guidelines for access control, threat detection, network congestion, regulatory compliance, and overall security posture hygiene.
Personnel use two main techniques to complete virtual segmentation: virtual local area network (VLAN) implementation and network virtualization.
Virtual Local Area Network (VLAN) Implementation
VLAN implementation is a perimeter-based segmentation technique that establishes internal and external subnetworks based on user trust and network access credentials. In general, segments created using VLAN implementation consider internal data and users to be trusted, whereas all external resources are not.
Initially, network security professionals used VLANs to improve on-premise network performance. However, over time, personnel have relied on VLANs as a security tool, which presents a significant problem as personnel never intended to use them for this purpose. Overall, VLANs support a broad level of access, which can create security problems for an organization that is looking to limit who can access sensitive information or data.
To combat the security weaknesses of VLAN implementation, organizations should create network segmentation policies that limit traffic flow from one segment to another based on traffic source, type, or end destination. Firewalls are also commonly used alongside VLANS to control north-to-south network traffic and permit lateral movement within segments.
Network virtualization is a segmentation technique that creates deep network segments by transferring network hardware to software. Security personnel utilize this popular technique to improve security in cases where cloud environments, bring-your-own-device (BYOD) policies, and independent mobile network devices have blurred an organization’s network perimeter.
By managing its entire network using software, organizations can continue to leverage physical network resources (switches, routers, firewalls, load balances, VPNs, etc.) while improving east-west traffic security with software-specific security controls, like Internet Protocol (IP) packet forwarding. IP packet forwarding allows organizations to easily permit users to access internal networks from independent IP addresses (essential for remote workers).
Software security services typically use virtual data center layers and are connected to virtual machines following network security policies. One of the main benefits of software-defined networking is that personnel can create new workloads at scale while applying policies consistently.
The Zero-Trust Response
Network virtualization is the most popular segmentation technique primarily because of the rise of zero-trust security policies. In the past, most network administrators only employed perimeter security practices to prevent outside access to internal networks. However, the main flaw with perimeter security is the assumption that every user inside a network is trustworthy.
Unlike perimeter security, which trusts all internal users, a zero-trust security model follows least privilege principles, verifying user identities in real-time. Least privilege access typically uses multi-factor authentication (MFA) or two-factor authentication (2FA) and authentication apps to verify user identity.
Organizations looking to implement zero-trust policies into their network security strategies can follow these steps:
- Step 1: Don’t trust users, verify their identity
- Step 2: Contextualize network requests
- Step 3: Secure admin environments
- Step 4: Implement least privilege
- Step 5: Audit everything
- Step 6: Use adaptive controls
Drawbacks of Network Segmentation
While network segmentation can benefit most organizations, the strategy also has limitations, hence why not all organizations have segmented their network. The main drawbacks of network segmentation include the following:
- High Costs (upkeep and implementation)
- Difficult to Manage/Implement
- Increased Misconfiguration Risks
- Potential Network Bottlenecks and Traffic Slowdown
- Not Applicable to All IT Infrastructures
How Can UpGuard Help?
UpGuard is an all-in-one cybersecurity solution that helps organizations improve their cyber hygiene, prevent data breaches, and identify vulnerabilities across their internal and external attack surfaces.
Organizations that maintain extensive supply chains and partner with many third-party service providers must protect their network and sensitive data from third-party risks. UpGuard Vendor Risk uses accurate security ratings to provide organizations with data-driven, objective, and dynamic measurements of their vendor’s security posture.
UpGuard’s toolbox of cybersecurity features also includes:
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