Why You Need to Monitor Your East-West Traffic

NETSCOUT’s “What and Why” series explores and explains the importance of east-west traffic network visibility for security.

NETSCOUT’s importance of east-west traffic network visibility for security.

In the ever-evolving landscape of cybersecurity, staying ahead of potential threats is paramount. One crucial aspect organizations cannot afford to overlook is east-west traffic monitoring. In this blog, we delve into the concept of east-west traffic, explore its importance for security, explain how effective monitoring can fortify an organization’s defenses, and address perceived barriers to implementing an east-west traffic monitoring solution.

Understanding East-West Traffic

Network traffic often is categorized into two main types: north-south and east-west. North-south traffic refers to communication between internal networks and external entities, such as clients accessing a website, or an external host accessing a company’s internal network. On the other hand, east-west traffic is the data flow between servers and devices within the internal network, also known as lateral movement. Examples of east-west traffic include corporate local area network (LAN) to regional offices, LAN to internal data centers, communication within internal data centers (e.g., front-end web server to back-end database server), or communication within a cloud-based data center. Traffic rates of east-west communication (i.e., hundreds of Gbps) are commonly much higher than north-south (Mbps-Gbps). And there are many more unique protocols within east-west traffic (e.g., web, database, custom apps) than within north-south (e.g., web).

Traditionally, the focus of security measures has been primarily on north-south traffic. However, with the rise of sophisticated cyberthreats and the proliferation of lateral movement techniques by attackers, the importance of east-west traffic monitoring has gained prominence.

Why East-West Traffic Monitoring Matters

  • Detecting lateral movement: East-west traffic monitoring is essential for detecting lateral movement, where attackers move horizontally within the network after gaining initial access. This is a critical aspect that north-south traffic monitoring may not adequately address.
  • Insider threat detection: Identifying malicious activities by insiders requires a focus on east-west traffic. Monitoring internal network communication helps detect unusual interactions between users and systems, mitigating the risk of insider threats.
  • Data exfiltration prevention: East-west traffic monitoring is crucial for preventing data exfiltration attempts. Detecting abnormal patterns in internal network activities allows organizations to respond promptly and protect sensitive information.
  • Zero-trust security model: Aligning with the zero-trust security model, east-west traffic monitoring continuously verifies and authenticates internal communications, reducing the risk of unauthorized access and lateral movement.
    Rapid incident response: In the event of a security incident, time is critical. Security-based east-west traffic monitoring provides real-time visibility into internal network activities, enabling quick responses to potential threats and minimizing the impact of security incidents.

The Risks of Neglecting East-West Traffic Monitoring

Although organizations may prioritize external threats addressed by north-south traffic monitoring, neglecting east-west traffic poses significant risks, including the following.

  • Undetected lateral movement: Without east-west traffic monitoring, lateral movement within the network may go unnoticed. Attackers can freely navigate, escalating privileges and compromising additional systems without triggering alarms.
  • Insider threats remain hidden: Internal threats, whether intentional or accidental, are harder to detect without east-west visibility. Malicious insiders can exploit this blind spot, leading to data breaches or other damaging activities.
  • Data exfiltration goes unchecked: The absence of east-west monitoring increases the likelihood of undetected data exfiltration. Data exfiltration often involves stages where sensitive information is first accessed or staged within the internal servers before being exfiltrated outside the company. The lack of east-west monitoring heightens the risk of overlooking these critical internal stages, potentially allowing data to leave the network unnoticed.
  • Compromised incident response: In the event of a security incident, the lack of east-west visibility hampers incident response efforts. Security teams may struggle to contain and eradicate threats swiftly, resulting in prolonged exposure and increased damage.
  • Ineffective zero-trust implementation: Neglecting east-west traffic monitoring undermines the principles of the zero-trust model. The organization cannot ensure continuous verification of internal communications, leaving potential entry points for attackers.
  • Compliance and auditing: Many industries have compliance requirements that necessitate monitoring and auditing of internal network communication. East-west traffic visibility ensures that organizations can meet these regulatory requirements.

Overcoming Hesitations to East-West Traffic Monitoring

Although the significance of east-west traffic monitoring is evident in enhancing internal network security, some organizations hesitate to invest in this crucial aspect due to various challenges. Recognizing and addressing these concerns is vital to implementing a comprehensive cybersecurity strategy. NETSCOUT, with its innovative Visibility Without Borders solutions, tackles these barriers, providing organizations with the confidence and capabilities needed to embrace east-west traffic monitoring. Common hesitations to east-west traffic monitoring investment include:

  • Resource constraints
    • Barrier: Organizations may perceive east-west traffic monitoring for security as resource-intensive, requiring significant investments in both technology and personnel.
    • Overcoming with NETSCOUT: NETSCOUT’s solutions, such as Omnis CyberStream, are designed to be scalable and cost-effective. The platform’s efficiency ensures comprehensive packet-level visibility without imposing excessive resource burdens on organizations.
  • Lack of scalability
    • Barrier: Scalability concerns may arise, especially for organizations anticipating growth or operating on a large scale.
    • Overcoming with NETSCOUT: NETSCOUT’s solutions, designed from the onset with scalability in mind, ensure that organizations can expand their east-west traffic monitoring efforts without compromising cost-effectiveness. The platform’s tried-and-tested philosophy involves packet capture of 100 Gbps, decoding of hundreds of protocols, and storing of all packets and metadata locally, allowing for scalability while maintaining efficient analysis even in the face of the largest networks.
  • Legacy infrastructure compatibility
    • Barrier: Organizations with legacy infrastructure may worry about the compatibility of east-west traffic monitoring solutions with their existing systems.
    • Overcoming with NETSCOUT: NETSCOUT’s solutions are designed with flexibility in mind. They seamlessly integrate with a variety of cybersecurity tools and legacy systems, ensuring compatibility and reducing disruptions during implementation.
  • Perceived return on investment (ROI)
    • Barrier: Some organizations may question the perceived ROI of east-west traffic monitoring, especially if they believe the internal network is less susceptible to threats.
    • Overcoming with NETSCOUT: NETSCOUT’s platform not only enhances security but also contributes to operational efficiency. By streamlining incident response, reducing mean time to resolution by improving mean time to knowledge, and providing historical investigation capabilities, NETSCOUT ensures a tangible and valuable ROI for organizations.
  • Concerns about false positives
    • Barrier: Fear of dealing with a high volume of false positives may make organizations hesitant about implementing east-west traffic monitoring.
    • Overcoming with NETSCOUT: NETSCOUT’s advanced instrumentation, utilizing multidimensional threat analytics and behavioral analysis to create a threat severity score, minimizes false positives. The platform’s targeted machine learning techniques ensure accurate threat detection, enhancing the effectiveness of security measures.



Omnis Cyber Intelligence (OCI) offers a comprehensive platform for advanced network threat detection and response based on scalable deep packet inspection (DPI). This Visibility Without Borders platform stands out in its ability to address not only north-south but also east-west traffic risks effectively, providing organizations with unparalleled visibility, multidimensional threat detection capabilities, and streamlined incident response workflows. With OCI, organizations can proactively fortify their defenses and safeguard against the dynamic cyberthreats of today and tomorrow.

Learn more about NETSCOUT’s Omnis CyberStream and Omnis Cyber Intelligence.