L3 Network Operations Engineer (Cisco/Arista)

Location: Cluj-Napoca, Romania; hybrid work with at least three days per week in the office. Standard Monday–Friday business hours, global follow-the-sun support across EMEA, APAC, and the Americas, and a shared weekend on-call rota for major incidents.

Company

Marsh is a global risk, reinsurance, capital, people and investments, and management consulting organization serving clients in 130 countries.

What you will do

• Provide L3 escalation support, technical triage, fault isolation, remediation, and service restoration for complex network incidents and major disruptions.
• Support enterprise LAN, WAN, branch connectivity, routing, switching, WiFi/WLAN, and on-premises infrastructure, including end-to-end connectivity investigations.
• Configure and troubleshoot Cisco and Arista routers and switches, including VLANs, trunking, Spanning Tree, SVIs, inter-VLAN routing, routing protocols, and high-availability configurations.
• Analyze traffic flows, routing paths, interface behavior, connectivity dependencies, latency, packet loss, carrier issues, and site-to-site communication.
• Implement network upgrades, migrations, hardware replacements, connectivity changes, site deployments, and infrastructure improvements through ITIL-aligned change governance.
• Coordinate with internal teams, service owners, carriers, vendors, technology partners, and suppliers; produce implementation plans, risk assessments, validation and rollback procedures, technical documentation, diagrams, ITSM records, and knowledge articles.

Requirements

• Proven L3 Network Operations, senior network support, or comparable enterprise, NOC, or infrastructure operations experience.
• Strong hands-on troubleshooting across LAN, WAN, branch networks, routing and switching, network paths and traffic flows, network availability and performance, WiFi/WLAN, and on-premises infrastructure.
• Solid Cisco multilayer switching experience covering Layer 2 and Layer 3 troubleshooting, VLANs, trunking, Spanning Tree, SVIs, inter-VLAN routing, routing protocols, and high-availability and resiliency concepts.
• Professional experience with Cisco and/or Arista routers and switches, plus practical troubleshooting of WAN connectivity, circuits, carrier issues, routing problems, and branch outages.
• Experience supporting enterprise WiFi environments, including wireless access points, controllers, switching dependencies, and wireless connectivity issues.
• Strong troubleshooting-level understanding of TCP/IP, DNS, DHCP, HTTP, HTTPS, and TLS.
• Experience analyzing symptoms, isolating root causes, implementing remediation, and supporting major incidents and complex technical escalations.
• Experience working with telecommunications providers, vendors, and third-party support organizations.
• Strong change-management discipline within an ITIL framework, including Incident, Problem, and Change processes; ability to produce clear documentation and communicate with technical and non-technical stakeholders.
• Ability to work independently and collaboratively in a global team, with willingness to participate in the shared weekend on-call rota.

Nice to have

• Experience as a Network Implementation Engineer, Senior Network Engineer, L3 Network Engineer, Network Infrastructure Engineer, Branch Network Engineer, or Network Operations Engineer.
• Experience with enterprise branch deployments, migrations, rollouts, infrastructure refreshes, new site openings, office relocations, branch migrations, and hardware replacement projects.
• Large-scale Cisco and/or Arista experience and advanced enterprise WiFi experience, including WLAN design, controllers, access points, site deployments, and complex wireless troubleshooting.
• Experience with SD-WAN, branch connectivity solutions, hybrid network environments, cloud-connected enterprise networks, network automation, or configuration tools.
• Relevant Cisco, Arista, networking, or ITIL certifications.
• Familiarity with firewalls, cloud security controls, Zero Trust, segmentation, load-balancing, or traffic-management technologies.
• Experience supporting network changes and implementations in a large, geographically distributed organization.

Culture & Benefits

• Hybrid work with office collaboration at least three days per week and a global network and infrastructure environment.
• Professional development, learning opportunities, supportive leadership, and an inclusive working environment.
• Yearly flexible-benefits budget of up to 20% of annual salary.
• 30+ days off, including legal days, birthday leave, public holiday replacements, and benefits options.
• Performance bonus, pension, life insurance, medical insurance, meal vouchers, travel insurance, and charity programs.
• Opportunities to contribute to global network improvements and large-scale infrastructure projects.