Senior Network Engineer

ON.energy is seeking a Senior Network Engineer to design, secure, and maintain network infrastructure of Operational Technology (OT) environments. This role requires deep expertise across network topologies, troubleshooting, and security, with a strong preference for hands-on experience securing industrial control networks using Palo Alto firewalls and Moxa switches.

KEY RESPONSIBILITIES

• Design, implement, and maintain OT network architectures, including LAN/WAN, wireless, and industrial network segments.
• Configure, manage, and troubleshoot Palo Alto next-generation firewalls to enforce network security policy and segmentation between OT zones.
• Deploy and maintain Moxa industrial switches and other ruggedized networking hardware in OT environments.
• Diagnose and resolve complex network issues across routing, switching, and security layers, minimizing downtime in production and industrial settings.
• Design and maintain VLAN structures, subnetting schemes, and IP addressing plans across OT networks.
• Configure and manage NAT, VPN tunnels, and site-to-site/remote access connectivity.
• Implement and maintain High Availability (HA) network designs to ensure resilience of critical infrastructure.
• Apply network security best practices, including segmentation, access control, monitoring, and hardening of OT networks.
• Collaborate with controls, automation, and cybersecurity teams to support integration of PLCs, SCADA systems, and industrial PCs onto the network.
• Document network designs, standard operating procedures, and change management records.

REQUIRED QUALIFICATIONS

• Expert-level knowledge of network topologies and structured troubleshooting methodology.
• Strong hands-on proficiency with TCP/IP, VLANs, routing, switching, subnetting, and NAT.
• Demonstrated experience designing and supporting site-to-site and remote access VPNs.
• Solid understanding of network security principles and High Availability design.
• Experience working within Operational Technology (OT) environments and an understanding of IT/OT network segmentation.
• Bachelor's degree in a related field, or equivalent professional experience.

PREFERRED QUALIFICATIONS

• Hands-on expertise with Palo Alto firewalls (policy configuration, App-ID, segmentation, VPN, and monitoring).
• Experience deploying and managing Moxa industrial switches.
• Familiarity with Siemens PLCs and industrial control system architectures.
• Experience with SEL (Schweitzer Engineering Laboratories) protective relay and communication devices.
• Experience networking and supporting Industrial PCs in production/OT environments.
• Familiarity with Ignition SCADA platform and its network/architecture requirements.
• Proficiency administering both Windows and Linux environments.
• Relevant certifications such as PCNSE, CCNA/CCNP, or similar are a plus.

CORE TECHNICAL SKILLS

Category	Skills
Networking Fundamentals	TCP/IP, VLANs, Routing, Switching, Subnetting, NAT
Security	Palo Alto Firewalls, VPNs, Network Security, High Availability
OT Hardware	Moxa Switches, Siemens PLCs, SEL Devices, Industrial PCs
Software/Platforms	Ignition SCADA, Windows, Linux

ON.energy is an equal opportunity employer. This job description is intended to convey information essential to understanding the scope of the role and is not exhaustive of all responsibilities, skills, or qualifications required.