Sr. Network Security Engineer

Total-TECH Co

The Job Description

1. Identify and clean up unused or orphaned IP addresses on F5 BIG-IP load balancers to improve performance, efficiency, and manageability.
2. Review, validate, and remove unused, duplicate, or obsolete firewall policies across HQ and DR data centers while maintaining security posture and compliance.
3. Ensure firewall and load balancer changes are aligned with high availability (HA) and disaster recovery (DR) requirements.
4. Perform a comprehensive assessment of all devices, applications, databases, and network components using public IP addresses.
5. Analyze application, service, and security dependencies to determine the potential impact of IP, firewall, and load balancer changes.
6. Classify firewall rules and DNS-related entries based on criticality, usage, activity level, and business relevance.
7. Design and allocate private IP address ranges, ensuring compatibility with existing network and security architecture.
8. Assess and analyze DNS records to identify unused, outdated, or invalid entries related to applications and security controls.
9. Remove or update invalid, obsolete, or unnecessary DNS records while ensuring no impact on applications or end users.
10. Execute cleanup and migration activities in a secure, controlled, and auditable manner, ensuring uninterrupted service continuity.
11. Coordinate with application, systems, SOC, and operations teams to align firewall rules, NAT, routing, DNS, and access controls.
12. Perform post-change testing and validation to confirm service availability, security enforcement, and performance stability.
13. Establish periodic review procedures for firewall rules, F5 configurations, IP addressing, and DNS records to ensure ongoing accuracy and security.
14. Ensure cleanup activities do not negatively impact applications, services, or end users.
15. Maintain comprehensive documentation for all activities, including changes implemented, issues encountered, root cause analysis, and approved remediation actions.
16. Support audit, compliance, and regulatory requirements through proper documentation and change tracking.
17. Develop detailed cleanup and migration plans including sequencing, timelines, backups, and rollback procedures.
    

    Requirements:
    

• Strong hands-on experience with firewalls (NGFW), security policies, NAT, and access control management.
• Proven expertise in F5 BIG-IP (LTM), including VIPs, Self IPs, SNATs, and HA configurations.
• Solid understanding of enterprise IP addressing, DNS, routing, and network security architecture.
• Experience operating in HQ / DR, high-availability, and mission-critical environments.
• Strong knowledge of change management, rollback planning, and risk mitigation.
• Bachelor s degree in Computer Science, Information Technology, or related field.
• Certifications such as CCNP Security, F5-CA/CTS, NSE, or equivalent are high.