Why East/West Traffic Needs Zero Trust

Zero trust is no longer just a concept—it’s essential. With cloud adoption, hybrid work, and increasingly sophisticated cyber threats, traditional perimeter security no longer suffices. Attackers exploit vulnerabilities inside networks, moving laterally undetected. Many organizations focus on securing north-south external-facing interactions while failing to monitor internal east-west traffic. This oversight exposes networks to ransomware, insider threats, and supply chain attacks. 

Enterprises must secure all network layers to fully realize zero trust, enforcing least-privilege access across external and internal traffic flows. A robust strategy prevents lateral movement, contains breaches, and mitigates risk. 

The Overlooked Risk: Unprotected East/West Traffic 

Modern enterprise networks have changed significantly. The once-centralized data center is now a distributed mix of remote users, SaaS applications, hybrid cloud, and IoT/OT devices. As a result, traditional security models designed for perimeter defense are no longer sufficient. 

North-south security measures such as firewalls, intrusion prevention systems (IPS), and secure web gateways (SWG) help block external threats. However, attackers who bypass these defenses can spread laterally through east-west traffic, moving between applications, workloads, and endpoints without detection. 

East-west traffic includes WAN-based communication between branch offices and internal LAN activity within sites. Organizations must secure WAN traffic with security services like SWG, CASB, and ZTNA and intra-LAN traffic through microsegmentation and access control. Without these measures, internal movement remains a blind spot, increasing the risk of data breaches and system compromise. 

How Attackers Exploit Lateral Movement 

Once inside a network, attackers use various techniques to spread. Credential compromise allows unauthorized access through stolen or weak passwords. Malware, including ransomware, propagates rapidly in unsegmented networks. Privilege escalation methods, such as Pass-the-Hash and Kerberoasting, enable attackers to gain control of critical systems. Data exfiltration can occur unnoticed if security policies do not monitor internal traffic. 

Without visibility and enforcement over east-west communication, organizations struggle to contain breaches. When security teams detect an issue, significant damage may have already occurred. 

Challenges in Securing East/West Traffic 

Despite the importance of internal security, several obstacles make the implementation of LAN or segmentation firewalls difficult. Legacy network architectures often rely on perimeter firewalls that lack visibility into internal traffic. Manual segmentation management is complex and prone to misconfiguration. Many IT teams struggle to monitor interactions between endpoints, workloads, and cloud applications. Additionally, traditional security tools can introduce latency, making inline enforcement impractical. 

To overcome these challenges, enterprises need a modern approach that integrates zero trust with scalable, efficient security controls for internal traffic. 

Microsegmentation: A Core Component of Zero Trust 

Microsegmentation is essential for preventing lateral movement within the network. It allows organizations to enforce identity-based policies, limiting communication between users, devices, and applications. Unlike traditional VLAN-based segmentation, which is static and difficult to manage, modern microsegmentation dynamically adjusts security rules based on real-time context. 

According to NIST Zero Trust guidelines, organizations should apply strict access policies within the network to minimize exposure. Effective microsegmentation uses identity, device, and application context to enforce security dynamically, restricts unnecessary connections between endpoints, and reduces risk without relying on rigid network configurations. 

Microsegmentation is a critical safeguard against internal threats for enterprises adopting zero trust. However, implementing it effectively requires an approach that avoids complexity while maintaining high-security standards. 

How Cato Networks Secures East/West Traffic 

Cato Networks extends zero trust security beyond the perimeter with a SASE-based microsegmentation approach. The LAN Next-Gen Firewall (NGFW), a native feature of the Cato SASE Cloud Platform, applies segmentation policies inside the network without requiring complex configurations or additional hardware. 

Identity-based microsegmentation enforces least-privilege access dynamically across LAN, WAN, and cloud environments. Instead of relying on static firewall rules, Cato applies security policies based on user, device, and application attributes. Deep Packet Inspection (DPI) ensures that internal traffic is continuously monitored for threats. Unlike ZTNA solutions that focus solely on external access, Cato secures traffic inside the network, preventing lateral movement. 

Benefits of Cato’s LAN Firewall for Zero Trust 

Cato’s LAN Firewall integrates seamlessly into the SASE Cloud Platform, offering security and simplicity in a single solution. It provides comprehensive visibility into internal communications, ensuring real-time monitoring of all branch-to-branch, cloud-to-cloud, and IoT/OT interactions. 

Enforcing least-privilege access minimizes risk by restricting unnecessary connectivity between workloads, applications, and devices. Unlike traditional segmentation methods, Cato’s cloud-native design scales dynamically, avoiding the complexity of appliance-based solutions. 

Threat prevention capabilities include built-in IPS, NGFW, and advanced intelligence to detect and neutralize malicious activity before it spreads. Cato simplifies security operations and reduces administrative overhead by unifying policy management across all locations within a single dashboard. 

With Cato’s LAN Firewall, enterprises strengthen their zero-trust strategy, closing internal security gaps while maintaining network agility. 

A Holistic Approach to Zero Trust Security 

Zero trust security must extend beyond external threats. Organizations that focus only on perimeter defenses are vulnerable to lateral movement, ransomware, and insider threats. To build a resilient security posture, enterprises must secure both north-south and east-west traffic. 

Cato Networks delivers a comprehensive approach to zero trust with cloud-native segmentation, dynamic policy enforcement, and deep traffic inspection. By integrating security across LAN, WAN, and cloud environments, Cato ensures that enterprises stay protected—inside and out. 

To take your zero trust strategy to the next level, explore how Cato Networks can help eliminate security blind spots and enhance internal threat protection. Get in touch today.