Senior OT Network Engineer

Job Title: Sr. OT Network Engineer
Job Location: Manassas, VA
Eligibility/Clearance: Must be authorized to work in the US

JOB DESCRIPTION

Architecture & Design

- Design and implement a segmented OT network architecture
transitioning from flat Layer 2 networks to SD-WAN-enabled,
zone-based architectures.

- Define network segmentation strategy (ISA/IEC 62443 zones and
conduits model) to isolate critical OT assets and control east-west
traffic.

- Engineer ring and/or resilient topologies across substations and
core OT sites to ensure deterministic communication and fault
tolerance.

- Develop SD-WAN design standards including:

- Underlay/overlay architecture

- Path selection policies (latency, jitter, packet loss)

- QoS for ICS protocols (e.g., DNP3, Modbus, IEC 61850)

Security & Compliance

- Develop and enforce OT-specific cybersecurity controls, including
micro-segmentation, firewall zoning, and least-privilege access.

- Define and implement firewall policies to restrict inter-zone
communication and prevent unauthorized access to OT systems.

- Conduct risk and vulnerability assessments aligned with OT threat
models (ransomware, lateral movement, supply chain risks).

- Ensure compliance with NERC CIP standards and other applicable
frameworks.

Implementation & Operations

- Lead deployment of SD-WAN solutions across OT sites, including
integration with existing switching infrastructure (e.g.,
industrial-grade switches).

- Configure and maintain high availability mechanisms:

- Redundant paths and failover (active/active or active/standby)

- Rapid spanning tree / ERPS / MPLS-TP where applicable

- Support incident response and root cause analysis for OT network
disruptions.

- Manage projects and deliver on time with periodic status reports to
management.

BASIC QUALIFICATIONS

- 10+ years of experience in network design and architecture,
preferably in OT environments.

- Experience with industrial protocols (e.g., Modbus, DNP3, OPC,
Ethernet/IP).

- Familiarity with IT/OT convergence principles.

DESIRED SKILLS

- Strong understanding of networking concepts, including routing,
switching, and firewall configurations.

- Proficiency in network monitoring and management tools.

- Knowledge of cybersecurity best practices for OT networks.

- Experience with industrial control systems (ICS) and SCADA systems.

MINIMUM TECHNICAL EXPERIENCE

- Knowledge of design, configuration, installation, testing, and
maintenance of local and wide area computer wired and wireless
networks (Cisco Systems preferred).

- Knowledge of computer network characteristics, network operating
system software, and network components

- Troubleshooting skills and the ability to diagnose/resolve network
system problems.

- Ability to interpret and apply complex technical manuals and
reference materials.

- Ability to assist with developing network security and related
procedures; and performing network management activities.

EDUCATION REQUIREMENTS

- Bachelor’s degree in computer science, computer networks, or a
related field.

- Certification in related fields (CCNA, CCNP) required. Security and
Cisco Certified Internetwork Expert (CCIE), and experience in
Extreme network switches is a plus.

Arena Technical Resources, LLC, (ATR) is an Equal Opportunity Employer
(EOE) who will provide equal employment opportunity to employees and
applicants for employment without regard to  race, ethnicity, religion,
color, sex, pregnancy, national origin, age, veteran status, ancestry,
sexual orientation, gender identity or expression, marital status,
family structure, genetic information, or mental or physical disability