L3 Network Operations Engineer

About the role

Marsh is looking for an L3 Network Operations Engineer to join its Network Operations team in Cluj-Napoca, under a hybrid model with at least three days per week in the office. The role is a senior escalation point for complex network incidents, service issues and network changes, with a focus on troubleshooting, problem resolution, remediation and implementation. It supports enterprise network services across LAN, WAN, branch connectivity, WiFi, routing, switching and on-premises infrastructure.

Key responsibilities

• Provide L3 escalation support for complex network incidents and major service disruptions, leading technical triage, fault isolation, remediation and service restoration.
• Troubleshoot LAN, WAN, branch, routing, switching, WiFi and on-premises issues, including IP, TCP, DNS, DHCP, HTTP/HTTPS and TLS.
• Analyse network traffic flows, routing paths and interface behaviour to find root causes.
• Support WAN and branch connectivity, including routing, pathing, latency, packet loss, circuits and site-to-site communication.
• Support branch LAN/WLAN and enterprise WiFi/WLAN environments, including access points, controllers and switching dependencies.
• Configure, support and troubleshoot Cisco and Arista routers and switches, including VLANs, trunking, Spanning Tree, SVIs, inter-VLAN routing and routing protocols.
• Work with carriers, vendors and managed service providers during outages and complex issues.
• Deliver network changes safely through ITIL-aligned governance, with plans, risk assessments, validation steps and rollback procedures.
• Implement upgrades, migrations, hardware replacements and site deployments, and take part in problem management and documentation.

Required profile

• Proven experience in L3 network operations, senior network support or a similar role in an enterprise, NOC or infrastructure operations environment.
• Strong hands-on troubleshooting experience across LAN/WAN, routing and switching, WiFi/WLAN and on-premises infrastructure.
• Experience with carriers, vendors and third-party support organisations, and with major incidents and complex escalations.
• Strong change management discipline within ITIL (Incident, Problem and Change processes).
• Ability to write clear technical documentation and communicate with technical and non-technical stakeholders.
• Willingness to join the shared weekend on-call rota for major incidents.

Required skills

• Solid experience with Cisco multilayer switching (Layer 2/3, VLANs, trunking, Spanning Tree, SVIs, routing protocols, HA).
• Professional experience with Cisco and/or Arista routers and switches.
• Core networking protocols at troubleshooting level: TCP/IP, DNS, DHCP, HTTP, HTTPS, TLS.
• Preferred: branch network deployments, enterprise WiFi with wireless controllers, SD-WAN, network automation tools, and certifications such as Cisco, Arista or ITIL.

What we offer

• A yearly budget and flexible benefits package of up to 20% of annual salary.
• 30+ days off, performance bonus scheme, matching charity contributions and core benefits including pension, life, medical and travel insurance.
• Professional development and learning opportunities.