What Is Network Security? Definition, Controls, and Examples

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What network security does

Network security gives teams the ability to:

See which devices, users, and applications are communicating.
Control who and what is allowed to connect.
Detect suspicious or malicious activity.
Contain threats before they spread

Attackers often rely on networks to move laterally, steal data, deploy ransomware, or disrupt operations. Securing these pathways reduces an attacker’s ability to gain a foothold and limits the impact of an incident.

How network security works

Network security uses layers of defense. These layers support confidentiality, integrity, and availability. No single control can protect an environment on its own, so organizations depend on multiple safeguards that work together and complement people and processes.

Core components include:

Access controls that determine who or what can connect.
Network segmentation that limits how traffic moves within the environment.
Monitoring and logging that capture activity for detection and investigation.
Threat detection that identifies abnormal behavior.
Response processes that contain confirmed threats.

As networks grow more distributed across cloud resources, endpoints, and external services, layered defenses help reduce blind spots.

Types of network security controls

Most organizations use several categories of network security controls.

Firewalls

Traffic is filtered based on defined rules that allow authorized access and block known malicious activity.

Intrusion detection and prevention systems

These systems inspect traffic for suspicious patterns, while intrusion detection systems alert teams and prevention systems can block activity.

Segmentation and microsegmentation

Systems are separated into controlled zones to limit an attacker’s ability to move laterally.

Zero trust network access

Users and devices are verified before access is granted. Trust is never assumed, and access is evaluated continuously.

Network access control

This ensures devices meet security requirements, such as patches and configuration baselines, before they connect.

Encryption

In-transit data is protected against interception or tampering.

DNS security

This process blocks known malicious domains and reduces exposure to phishing, malware, and command-and-control activity.

Secure web gateways

Outbound traffic is inspected and access to unsafe destinations prevented.

Email and messaging security

This process identifies phishing attempts, unsafe attachments, and impersonation tactics.

Cloud network security

With this process, teams can use virtual firewalls, security groups, and workload policies to manage traffic between cloud resources.

Network behavior analytics

Network activity is analyzed in an effort to detect unusual data transfers or user behavior that may indicate early attack stages.

Common network security threats

Threats targeting networks range from simple to highly sophisticated. Common examples include:

Malware
Phishing and other social engineering techniques
Man-in-the-middle attacks
Distributed denial-of-service attacks
Ransomware
Unsecured Wi-Fi or rogue access points
Lateral movement after initial compromise
Exploitation of known vulnerabilities

Network security in modern environments

Today’s networks span on-premises systems, cloud architectures, remote workers, mobile devices, operational technology, and SaaS applications. This creates complex environments with more potential pathways for attackers.

Teams often face challenges such as:

Inconsistent log quality and many data sources.
Shadow IT and unmanaged devices.
Increasing cloud complexity.
Limited visibility into how users and workloads communicate.

Research from Rapid7 shows that network-based signals play a central role in investigations and that gaps in visibility slow detection and containment. Strong network security helps unify signals, reduce operational noise, and give analysts what they need to understand activity across environments.

Network security best practices

Improving network security requires consistent processes and collaboration across teams. Recommended practices include:

Maintaining an accurate asset inventory.
Using strong authentication and multifactor authentication.
Applying least-privilege access (LPA) principles.
Using segmentation to limit lateral movement.
Encrypting data in transit.
Continuously monitoring network traffic.
Patching and updating systems on a regular schedule.
Preparing for incidents through tabletop exercises and documented workflows.

These practices help reduce risk and strengthen overall resilience.

How network security compares to related concepts

Network security vs cybersecurity

Cybersecurity covers all digital systems and data. Network security focuses specifically on protecting communication pathways and the systems connected to them.

Network security vs cloud security

Cloud security protects workloads, identities, and infrastructure in cloud environments. Network security focuses on how those resources communicate, whether on-prem or in the cloud.

Network security vs endpoint security

Endpoint security protects individual devices. Network security protects the communication paths between those devices and systems.

Network security and zero trust

Zero trust complements network security by enforcing continuous verification and restricting access until conditions are met.

The role of network security in detection and response

Network visibility helps analysts identify attacks early and understand attacker movement. Alerts from firewalls, intrusion detection and prevention systems (IDPS), identity tools, and network traffic analysis (NTA) provide insight into suspicious behavior.

Strong network security supports teams by helping them:

Detect unusual activity such as privilege misuse or data exfiltration.
Trace attacker movement across systems.
Maintain logs needed for investigations.
Contain threats across segmented networks.

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What is Network Security?