Network Engineer L3+ (ACI)

Job Description – Network Engineer L3+ / Cisco ACI

Position: Network Engineer – L3+
Experience: 9+ Years Overall | 4–5 Years Relevant Experience
Location: BKC, Mumbai
Work Mode: Work from Office (WFO)
Shift: Rotational Shifts Applicable

Job Summary

We are looking for an experienced Network Engineer – L3+ with strong hands-on expertise in Routing, Switching, and Cisco ACI to manage, troubleshoot, and support enterprise network infrastructure. The candidate will be responsible for L3-level incident resolution, network performance, configuration, troubleshooting, and implementation across data center and enterprise environments.

Key Responsibilities

• Manage and troubleshoot enterprise LAN/WAN and Data Center networks at L3 level, ensuring high availability, performance, and SLA compliance.
• Strong hands-on experience with Cisco ACI (Application Centric Infrastructure) including fabric architecture, tenants, VRFs, Bridge Domains, EPGs, contracts, VLAN/VXLAN, and endpoint troubleshooting.
• Configure and troubleshoot Cisco routing and switching technologies including OSPF, BGP, EIGRP, VLAN, STP/RSTP/MST, EtherChannel, HSRP/VRRP, and TCP/IP.
• Perform advanced troubleshooting of routing, switching, connectivity, packet loss, latency, interface, VLAN, routing protocol, and network performance issues.
• Manage data center networking, including spine-leaf architecture, VXLAN/EVPN concepts, Layer 2/Layer 3 connectivity, and redundancy.
• Handle complex L3 incidents, problem management, RCA, and service restoration activities within defined SLAs.
• Perform network configuration, upgrades, migrations, maintenance activities, and implementation of approved changes following change-management processes.
• Monitor network health and performance using NMS/monitoring tools, analyze alerts, and proactively identify potential issues.
• Troubleshoot network security and connectivity issues involving firewalls, ACLs, NAT, VPN, load balancers, and network security controls.
• Work with Cisco, Palo Alto/Fortinet/Cisco Firepower, F5 or other OEM technologies as part of enterprise network infrastructure.
• Coordinate with ISP, OEM, NOC, Security, Server, Cloud, and Application teams for complex incidents and infrastructure changes.
• Participate in major incident/bridge calls, provide technical leadership, and drive incidents through resolution.
• Maintain network documentation, topology diagrams, configuration standards, operational procedures, and knowledge-base articles.
• Conduct capacity planning, network optimization, vulnerability remediation, firmware/software upgrades, and lifecycle activities.
• Support ITIL-based Incident, Problem, Change, and Service Request management processes.

Required Technical Skills

Primary Skills:

• Cisco ACI
• Cisco Routing & Switching
• Enterprise LAN/WAN
• Data Center Networking
• L3 Troubleshooting

Routing & Switching:

• BGP, OSPF, EIGRP
• VLAN, Trunking, STP/RSTP/MST
• EtherChannel/LACP
• HSRP/VRRP
• TCP/IP, ARP, DHCP, DNS
• IPv4/IPv6
• Routing and switching troubleshooting

Cisco ACI:

• ACI Fabric architecture
• APIC administration
• Spine & Leaf
• Tenants, VRFs, Bridge Domains
• EPGs and Contracts
• VLAN/VXLAN
• Endpoint learning and troubleshooting
• L2/L3 Outside Connectivity
• ACI fault and health-score analysis

Additional Networking Skills:

• Cisco Nexus/Catalyst platforms
• SD-WAN concepts
• Network security fundamentals
• Firewalls, ACLs, NAT and VPN
• Load Balancers – F5 or equivalent
• Wireless networking fundamentals
• Network monitoring and management tools
• Packet analysis using Wireshark/TCPDump
• Network automation/Ansible or Python is an added advantage
• Cloud networking concepts – AWS/Azure is an advantage

Experience & Qualifications

• 9+ years of overall experience in Network Engineering/Infrastructure.
• 4–5 years of relevant hands-on experience in enterprise/data center networking with strong exposure to Cisco ACI, Routing and Switching.
• Strong experience in L3 production support and complex network troubleshooting.
• Experience working in 24x7 enterprise environments and rotational shifts.
• Strong analytical, troubleshooting, communication, documentation, and stakeholder-management skills.
• Relevant Cisco certifications such as CCNP Data Center / CCNP Enterprise will be an added advantage