Network Segregation and Security Monitoring Policy
Purpose
To safeguard internal network resources by enforcing network segregation and deploying security tools to detect and mitigate external threats effectively.
Scope
This policy applies to all network infrastructure, devices, and personnel accessing or managing organizational networks.
Policy Statements
- Network Segregation
- Segmentation: Divide the network into distinct zones based on function, sensitivity, and access requirements (e.g., internal, DMZ, guest, and external-facing segments).
- Access Control: Implement strict access controls between segments using firewalls, VLANs, or software-defined networking (SDN) to limit lateral movement and restrict unauthorized access to internal resources.
- Internal Network Protection: Ensure internal network segments (e.g., employee workstations, servers) are isolated from external or less-trusted zones (e.g., guest Wi-Fi, vendor systems).
- Traffic Filtering: Use firewalls to filter and inspect traffic between segments, allowing only explicitly permitted communications based on business needs.
- Deployment of Network Security Tools
- Network Intrusion Detection System (NIDS):
- Deploy NIDS at strategic points (e.g., network perimeter, critical segment boundaries) to monitor incoming and outgoing traffic for suspicious activity.
- Configure NIDS to detect known attack signatures, anomalies, and potential external threats (e.g., DDoS, malware, reconnaissance attempts).
- Ensure real-time alerts are sent to the security team for analysis and response.
- Host-based Intrusion Prevention System (HIPS):
- Install HIPS on critical endpoints (e.g., servers, workstations with sensitive data) to monitor and block malicious activities at the host level.
- Configure HIPS to prevent unauthorized changes to system files, detect malware execution, and log suspicious behavior.
- Regularly update HIPS rulesets to address emerging threats.
- Monitoring and Response
- Continuous Monitoring: Enable 24/7 monitoring of network traffic and endpoint activity using NIDS and HIPS logs.
- Integration: Integrate NIDS and HIPS with a centralized Security Information and Event Management (SIEM) system for consolidated threat analysis and correlation.
- Incident Response: Establish a process to investigate and respond to alerts generated by NIDS and HIPS, including escalation procedures for confirmed threats.
- Maintenance and Compliance
- Updates: Regularly update NIDS signatures, HIPS policies, and firewall rules to address new vulnerabilities and threats.
- Testing: Conduct periodic penetration testing and vulnerability assessments to validate the effectiveness of network segregation and security tools.
- Audit: Perform quarterly reviews insular of network access logs and security tool performance to ensure compliance with this policy.
Roles and Responsibilities
- IT Team: Configures and maintains network segregation and security tools.
- Security Team: Monitors alerts, investigates threats, and updates detection rules.
- Management: Approves policy enforcement and ensures resource availability.
Enforcement
Non-compliance with this policy may result in restricted network access or disciplinary action, depending on organizational guidelines.