Senior L3 Engineer Network, Load Balancer & Security

1. Job Purpose

To provide L3 technical support and operations for enterprise network and security infrastructure, including routing and switching, load balancers, firewalls, and network security solutions. The role is responsible for troubleshooting complex incidents, ensuring high availability, performing root cause analysis, implementing approved changes, and maintaining SLA compliance in a mission-critical data centre environment.

2. Key Responsibilities

A. Routing & Switching

• Provide L3 support for enterprise and data centre network infrastructure.
• Configure, manage, and troubleshoot routers, switches, and network connectivity.
• Troubleshoot routing protocols, including BGP, OSPF, static routing, and route redistribution.
• Manage VLANs, trunking, STP, EtherChannel, HSRP/VRRP, and high-availability configurations.
• Troubleshoot complex network issues involving packet drops, latency, routing loops, and connectivity failures.
• Support network upgrades, firmware updates, configuration backups, and network optimization.
• Perform network configuration reviews and maintain updated network diagrams and documentation.

B. Load Balancer Operations

• Provide L3 support for application delivery controllers and load-balancing infrastructure.
• Configure and troubleshoot virtual servers, pools, nodes, health monitors, and traffic distribution policies.
• Support Layer 4 and Layer 7 load balancing, SSL/TLS offloading, persistence, and application traffic management.
• Troubleshoot application availability, session persistence, certificate, and backend connectivity issues.
• Manage high availability, failover, configuration backup, and software upgrades.
• Coordinate with application and server teams to resolve end-to-end service issues.

C. Firewall & Network Security

• Provide L3 support for enterprise and data centre firewalls.
• Configure and troubleshoot security policies, NAT, ACLs, VPNs, and site-to-site connectivity.
• Manage firewall rule changes, security policy reviews, and rule optimization.
• Troubleshoot IPsec and SSL VPN connectivity and authentication issues.
• Support firewall high availability, failover, software upgrades, and configuration backup.
• Analyze traffic logs and security events to identify and resolve connectivity and policy-related issues.
• Coordinate with security teams for vulnerability remediation, security hardening, and compliance requirements.

D. Security Operations & Incident Management

• Troubleshoot network security incidents and support investigation of suspicious traffic.
• Work with SIEM and monitoring teams to correlate network and firewall events.
• Support network segmentation, secure access, and security control implementation.
• Handle critical incidents, perform root cause analysis (RCA), and implement corrective and preventive actions.
• Manage incidents, problems, and changes in ITSM tools in accordance with approved procedures.
• Participate in planned maintenance, disaster recovery tests, and business continuity activities.

E. Service Delivery & Documentation

• Ensure compliance with agreed SLAs, operational procedures, and change management processes.
• Coordinate with L1/L2 support teams, application teams, OEMs, and customer stakeholders.
• Maintain SOPs, configuration records, network diagrams, and troubleshooting documents.
• Prepare incident reports, RCA reports, and operational status updates.
• Provide technical guidance to L1/L2 engineers and support knowledge transfer.

3. Required Technical Skills

Technology area

Required skills

Routing & Switching

BGP, OSPF, VLAN, STP, HSRP/VRRP, ACLs, TCP/IP

Load Balancers

F5 BIG-IP, Citrix ADC, or equivalent enterprise ADC platforms

Firewalls

Palo Alto, Fortinet, Check Point, Cisco, or equivalent

Network Security

IPsec/SSL VPN, NAT, security policies, segmentation, traffic analysis

Troubleshooting

Packet captures, Wireshark, TCP/IP analysis, log analysis

Operations

NMS monitoring, ITSM, incident/change/problem management, RCA

High Availability

Redundancy, clustering, failover, disaster recovery and configuration backup

4. Qualification & Experience

• Bachelors degree or diploma in Computer Science, IT, Electronics, or a related discipline.
• 812 years of experience in enterprise network and security operations.
• Strong hands-on experience in L3 troubleshooting of routing, load balancers, and firewalls.
• Experience supporting mission-critical data centre or enterprise network environments.
• Proven experience in major incident management, RCA, change implementation, and SLA-driven operations.
• Relevant certifications such as CCNP Enterprise, CCNP Security, PCNSE, F5 BIG-IP, or equivalent are desirable.

5. Key Performance Indicators (KPIs)

• Compliance with network and security SLAs.
• Timely resolution of L3 incidents and reduction in MTTR.
• Successful execution of approved changes without service disruption.
• Quality and timeliness of RCA and corrective actions.
• Reduction in recurring network and security incidents.
• Compliance with firewall policy, configuration backup, and security review procedures.

6. Working Requirements

• Willingness to work in a 24X7 operational environment, including rotational shifts and on-call support, if required.
• Ability to support critical production incidents and planned maintenance windows.
• Strong analytical, communication, documentation, and customer coordination skills.

Preferred candidate profile: An experienced L3 engineer with strong hands-on expertise in routing, load balancers, and firewalls, capable of independently troubleshooting complex network and security issues in a mission-critical data centre environment.