Network Support Lead L3

Location: Brooklyn (NY) |
Employment Type: Full Time - 40 hours per week |
Job Level: T6 |
Work Preference: Onsite at work location address |
Job Code: 245613

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Take technical ownership of complex enterprise networking challenges in a role that combines advanced troubleshooting, network security, architecture support, performance optimization, and technical leadership. As a Senior Network Support Lead (L3), you will serve as the final escalation point for critical network issues, lead high-severity incident resolution, manage Fortinet firewall environments, and drive improvements in network reliability, security, and operational efficiency.

You will also mentor junior engineers and contribute to network automation, infrastructure changes, and enterprise network design initiatives.

Advanced Troubleshooting & Incident Management

• Serve as the final L3 escalation point for complex network issues involving QoS, OSPF, BGP, VLANs, STP, port channels, NAT, ACLs, and VPNs.
• Perform advanced packet and traffic analysis using tools such as Wireshark, Forti Analyzer, and Syslog.
• Lead P1/P2 incident bridge calls, drive root cause analysis, and ensure timely resolution.
• Contribute to and review high-level and low-level designs (HLD/LLD) for new sites, migrations, segmentation initiatives, and firewall architectures.
• Validate designs for scalability, security, and compliance with enterprise standards.
• Recommend improvements across routing, switching, wireless, and network security.

Firewall & Network Security

• Manage and optimize Fortinet Forti Gate environments, including policies, NAT, UTM profiles, VPNs, routing, and high availability (HA).
• Audit firewall rules to support least-privilege access and compliance.
• Support network segmentation, hardening, and compliance initiatives.

Network Optimization & Reliability

• Perform capacity planning, traffic analysis, and network performance tuning.
• Monitor network health and proactively address recurring or systemic issues.
• Implement preventive measures and resiliency improvements.

Automation & Tooling

• Develop and maintain automation scripts using Python, Bash, and EEM.
• Automate configuration backups, compliance checks, and monitoring integrations.

Change Management & Migrations

• Lead major network changes, upgrades, firewall migrations, and routing redesigns.
• Prepare requests for change (RFCs), rollback plans, risk assessments, and post-change reports.
• Coordinate with application, infrastructure, security, and ISP teams.
• Work with ISPs and OEMs, including Cisco and Fortinet, on escalations, TAC cases, and hardware issues.
• Validate circuit performance and support last-mile troubleshooting.

Documentation & Technical Leadership

• Maintain network diagrams, SOPs, configuration standards, and runbooks.
• Improve L1/L2 documentation and operational processes.
• Mentor L1/L2 engineers and promote best practices in troubleshooting and network operations.
• Contribute to training plans, technical standards, and continuous improvement initiatives.

• 10–12 years of networking experience, including 3–4 years in L3 or senior escalation roles.
• Extensive hands‑on experience with Cisco IOS/XE and NX‑OS.
• Strong expertise in routing protocols, including OSPF and BGP, and switching technologies, including VLANs, STP, and Ether Channel.
• Strong experience with Fortinet Forti Gate (FortiOS) and Meraki wireless.
• Experience with SD‑WAN, VXLAN, Cisco DNA Center (DNAC), and Cisco ISE.
• Solid understanding of network security, VPNs, QoS, and segmentation.
• Experience with…