1. Introduction
2. What We Will Cover
3. NSX Component Hardening
   1. NSX Manager Security Configuration
   2. NSX Network Service Hardening
4. NSX Configuration Deployment & Enforcement
5. NSX Compliance & Regulatory Frameworks
   1. Network Segmentation (Micro-segmentation)
   2. API and Management Plane Security
   3. Audit Events & Logging
6. Operationalizing NSX Security: Monitoring, Compliance & Audit Events
   1. Monitoring Security Operations
   2. Viewing and Configuring Compliance
   3. Viewing and Configuring Audit Events
7. Conclusion

Introduction

For Security Architects/Platform Engineer, NSX Data Center is the strategic control plane for network and security within VMware Cloud Foundation (VCF) 9.0. It delivers fundamental capabilities like micro-segmentation, logical routing, and advanced firewalling, all critical for securing a modern Software-Defined Data Center (SDDC). This guide details essential technical hardening controls for NSX, informed by the official Broadcom VCF 9.0 Security and Compliance documentation click here its alignment with key regulatory frameworks, and vital operational security practices, directly applicable to VCF 9.0 deployments.

What We Will Cover

• Part 1: VCF 9.0 Management Plane Security: Hardening & Regulatory Compliance: We will explore securing the hypervisor (ESXi), central management (vCenter Server), the SDDC Manager, and the underlying virtual machines that host these critical management components. This section will include detailed technical controls, how they contribute to viewing and configuring compliance, monitoring security operations, and viewing and configuring audit events, all mapped to compliance frameworks like FISMA/NIST, PCI DSS,DISA STIG and HIPAA.
  https://puneetsharma.blog/2025/11/04/part-1-vcf-9-0-management-plane-security-hardening-regulatory-compliance/
• Part 2: NSX Security Hardening & Regulatory Compliance: This section will focus on leveraging NSX Data Center for network virtualization and security, covering NSX Manager, logical routing, and micro-segmentation controls crucial for regulatory adherence.
  https://puneetsharma.blog/2025/11/27/part-2-vcf-9-0-nsx-security-hardening-regulatory-compliance/
• Part 3: vSAN Security Hardening & Regulatory Compliance: We will delve into protecting your software-defined storage, detailing vSAN data-at-rest and in-transit encryption, access controls, and how these features contribute to data integrity and confidentiality requirements.

NSX Component Hardening

Effective NSX hardening ensures the integrity of network services and the management plane.

NSX Manager Security Configuration

The NSX Manager appliances control the entire NSX fabric; their security is paramount.

• Access Control & Authentication:
  • max-auth-failure-lockout-webui-CLI: Configure maximum authentication failures (e.g., 3 attempts, 15-minute lockout) for both Web UI and CLI, as per organizational policy.
  • password-complexity-webui: Enforce strong password policies for Web UI access, ensuring a minimum of 12 characters and including mixed case, digits, and special characters.
  • inactive-timeout-webui-CLI: Configure inactive session timeouts for Web UI (HTTP session timeout) and CLI (e.g., 15 minutes), as per organizational policy.
  • secure-nsx-aaa-ldap--channel: Ensure NSX Manager communication to LDAP servers for authentication exclusively uses TLS (LDAPS).
  • secure-nsx-vidm-channel: Ensure NSX Manager communication to vIDM uses TLS for secure identity management integration.
  • limit-user-role: Utilize roles and privileges within NSX Manager to limit user privileges based on job function.
  • limit-user-scope: Define granular Access Scope for NSX Manager users to restrict their view and modification capabilities.
• Communication & System Integrity:
  • disable-ssh-manager: Disable Secure Shell (SSH) access unless needed for diagnostics or troubleshooting; disable root login.
  • restrict-nsx-access: Restrict direct network access to NSX Manager appliance to authorized management networks/jump hosts.
  • block-unused-ports: Explicitly block access to ports not used by NSX Manager services via appliance firewall rules.
  • enable-ntp: Configure authorized NTP servers for precise time synchronization.
  • secure-nsxmanager-access-with-TLS1.2: Configure NSX Manager WEB/API access to use only TLS 1.2 or higher, disabling older TLS versions.
  • ensure-valid-certificates: Ensure NSX Manager uses valid, legitimate certificates from a trusted CA.
  • monitor-api-use: Configure API rate limits and concurrency limits to prevent abuse or denial-of-service against the NSX Manager API.
  • service-resilience: Configure DRS anti-affinity rules for multi-node Manager deployments across ESXi hosts.

NSX Network Service Hardening

Secure logical network services provided by NSX Gateways.

• Router Configuration (Tier-0, Tier-1 Gateways):
  • nsx-9.dhcp-disable: Disable DHCP services unless required.
  • nsx-9.inactive-interfaces: Remove all inactive interfaces.
  • nsx-9.multicast-disable: Disable PIM where not required.
  • nsx-9.ospf-encryption: Enable OSPF encryption (e.g., MD5 authentication).
  • nsx-9.reverse-path-forwarding: Configure uRPF in strict mode on Tier-0/Tier-1 interfaces.

NSX Configuration Deployment & Enforcement

Hardened configurations, derived from the VMware NSX Configuration Guide (VNCG) and VCF best practices, are applied through various VCF and NSX mechanisms.

Capture 1: –

Step 1: – Click on Security.
Step 2: – Click on Compliance.
Step 3: – Click on Enable under NSX Security Configuration Guide.

Capture 2: –

Step 4: – Select the default Policy.
Note: – We can make our own policy instead of default policy go to Infrastructure Operations –> Configurations –> Policy definition.
Step 5: – Click on Enable.

Capture 3: –

Step 6: – It will start running the initial assessment.
Note: – This process will take the 5 mins in my lab environment and it is dependent on the environment inventory.

Capture 4: –

Step 7:- There are 02 Non Compliant Checks.
Note: – These compliance/Non Compliance alerts vary on each environment and i make my lab non complaint just to show the alerts and recommendations.
Step 8: – Group by i selected Criticality.

Capture 5: –

Let’s go with a NSX example and try to find out why NSX is in violation state and what best practices are missing .
9. Expand the NSX Violation.
10. Select the NSX is violating VMware NSX Security Configuration Guide.
Note: – This is just an example to see the NSX non complaint alerts.

Capture 6: –

11. Click on Alerts.
Note: – We can see the best practices are not complaint on NSX-lb-a, we will follow the symptoms and remediate as per the security guidelines.

The NSX Security Configuration Guide is a comprehensive document provided by VMware by Broadcom that offers guidance and best practices for securing NSX Click Here .

NSX Compliance & Regulatory Frameworks

NSX Data Center capabilities are instrumental in meeting various compliance mandates.

Network Segmentation (Micro-segmentation)

NSX DFW enables fine-grained segmentation, directly supporting:

• PCI DSS 2.2 (Secure Configurations): Isolating CDE components at the vNIC level to limit traffic to essential flows.
• FISMA/NIST SP 800-53 SC-7 (Boundary Protection): Creating granular security zones within the SDDC for traffic control.
• ISO 27001 A.13.1.3 (Segregation in networks): Enforcing strict traffic separation independent of physical topology.

API and Management Plane Security

NSX Manager controls (account lockout, secure SSH, TLS ciphers, valid certificates) contribute to:

• FISMA/NIST SP 800-53 AC-7 (Unsuccessful Login Attempts): Limiting brute-force attacks against management interfaces.
• FISMA/NIST SP 800-53 SC-8 (Transmission Confidentiality and Integrity): Protecting management traffic and routing information.
• FISMA/NIST SP 800-53 CM-6 (Configuration Settings): Ensuring secure configurations for the NSX management plane (e.g., secure-nsxmanager-access-with-TLS1.2, ensure-valid-certificates).
• PCI DSS 8.2.1 (Strong Passwords): password-complexity-webui directly supports enforcing strong password strength.

Audit Events & Logging

NSX Manager’s robust logging supports:

• FISMA/NIST SP 800-53 AU-2 (Audit Events): Capturing security-relevant actions.
• PCI DSS 10 (Track and Monitor): Providing detailed audit trails for NSX configurations.
• enable-remote-syslog: Configuring remote logging for NSX Manager is crucial for these audit requirements.

Note: NSX provides technical mechanisms for compliance; actual compliance requires proper implementation, operational adherence, and documentation.

Operationalizing NSX Security: Monitoring, Compliance & Audit Events

Continuous monitoring and robust audit management are crucial for maintaining NSX security and compliance.

Monitoring Security Operations

• NSX Manager Logs: Monitor logs (nsx-9.log-level set to info) for configuration changes, API calls, and user activity.
• monitor-api-use: Actively monitor configured API rate limits and concurrency limits to detect potential abuse or DDoS attempts against the NSX Manager API.
• vDefend/Distributed Firewall (DFW) Logging: Enable logging on DFW rules for critical or audited traffic. Monitor these logs via SIEM for policy violations or unauthorized access.
• NSX Intelligence/Security Intelligence: Leverage for continuous network flow visibility, policy validation, and anomaly detection to verify micro-segmentation effectiveness.
• monitor-portscan-attack: Implement mechanisms to monitor for any possible port scan attacks directed at NSX Manager interfaces.

Viewing and Configuring Compliance

• Tools: Utilize VMware Cloud Foundation Operations for Networks for NSX compliance checks, assessing configurations and DFW rules against security best practices and compliance frameworks.
• Configuration: Regularly review NSX configurations (e.g., DFW rule sets, Gateway policies) to ensure alignment with desired security posture and evolving compliance requirements..

Viewing and Configuring Audit Events

• Centralized Syslog and SIEM: NSX Manager audit logs must be sent to an external, tamper-proof SIEM. Configure remote syslog via NSX Manager UI/API (enable-remote-syslog)..
• Log Integrity & Retention: Ensure logs are retained and protected from tampering as per regulatory requirements.
• Audit Event Analysis: Utilize SIEM dashboards/queries to correlate NSX events (e.g., failed logins, DFW rule changes, nsx-9.reverse-path-forwarding events for IP spoofing).

Conclusion

NSX is pivotal to VCF 9.0 network security.NSX is confirmed as a critical infrastructure component for enforcing network security within the VCF 9.0 architecture.NSX provides the technical primitives necessary for maintaining a secure, compliant, and auditable network environment within VCF 9.0.

Key technical aspects include:

• Threat Containment and Compliance: Micro-segmentation effectively limits the lateral movement of threats within the Software-Defined Data Center (SDDC). This capability is critical for satisfying specific regulatory compliance controls, such as those stipulated by PCI DSS and FISMA/NIST SC-7.
• Operational Requirements for Platform Engineers: Effective management of the VCF 9.0 environment requires Platform Engineers to possess specialized expertise in specific NSX functions. This includes the technical tasks of hardening NSX components, designing and implementing granular security policies, and proficiently utilizing the platform’s native monitoring and auditing tools.
• Proactive Security Posture: The proficient application of these NSX features enables capabilities for proactive threat detection, structured incident response, and the maintenance of continuous regulatory adherence within the VCF 9.0 infrastructure.