L3 Senior Network Engineer - Enterprise Infrastructure
First seen by Alion on Oct 17, 2026.
Role Summary :
We are seeking a highly skilled Senior Network Engineer (L3) to lead the engineering and operational management of a large-scale enterprise network infrastructure. This role is responsible for providing technical leadership, resolving complex network issues, driving automation initiatives, mentoring L2 engineers, and ensuring high availability, security, and performance across the global network environment.
Key Responsibilities :
- Provide technical leadership for enterprise network infrastructure and lead troubleshooting of complex network incidents (P1/P2/P3).
- Perform root cause analysis for recurring issues and design/review routing, switching, firewall, and load-balancing solutions.
- Lead network modernization, optimization, and infrastructure lifecycle management (firmware/OS upgrades, capacity planning).
- Develop automation using Python, PowerShell, Ansible, and REST APIs for configuration deployment and health checks.
- Implement and optimize monitoring tools like SolarWinds, LogicMonitor, PRTG, Cisco DNA Center, Splunk, and Grafana.
Required Technical Skills :
- Routing & Switching : Cisco Catalyst, Cisco Nexus, Aruba, Juniper.
- Protocols : BGP, OSPF, EIGRP, HSRP, VRRP, STP, EtherChannel, VXLAN.
- Firewalls : Palo Alto, Cisco Firepower, Fortinet, Check Point.
- Load Balancers : F5 BIG-IP, Citrix ADC (NetScaler).
- Wireless & SD-WAN : Cisco WLC, Aruba Wireless, Cisco SD-WAN, VMware VeloCloud, Fortinet SD-WAN.
- Cloud Networking : Azure, VPN Gateway, ExpressRoute, Direct Connect.
- Automation : Python, PowerShell, Ansible, Git, REST APIs.
Preferred Certifications :
- Cisco CCNP Enterprise (Required), Cisco CCIE Enterprise (Preferred), Palo Alto PCNSE, Fortinet NSE, F5 Administrator, ITIL Foundation.
Skills
Network Infrastructure, Routing & Switching, Routing Protocols, Troubleshooting, Network Load Balancing, Performance Tuning, Incident Management, Python, Juniper, BGP