Sr. Network Engineer w/active Top Secret clearance

LMI is seeking a skilled Network Engineer to design, build, maintain, and sustain classified network infrastructure supporting enterprise IT operations across three geographically dispersed government sites, including two greenfield SCIF facilities serving TS/SCI users. This individual will work with cross-functional teams to ensure reliable, secure connectivity across multiple locations.

Primary duties include:

Design, implement, configure, test, maintain, and sustain enterprise network infrastructure and services across all sites.

• Develop logical and physical network designs based on performance, availability, security, and operational requirements.

• Engineer resilient connectivity across sites, datacenters, cloud, wide-area networks, and other distributed environments.

• Apply sound principles for addressing segmentation, routing, switching, traffic management, and access control.

• Monitor network health, capacity, latency, availability, and utilization.

• Troubleshoot complex network issues using structured analysis, packet-level inspection, telemetry, logs, and performance data.

• Establish redundancy, failover, fault isolation, and recovery mechanisms.

• Integrate network security controls consistent with zero-trust and defense-in-depth principles.

• Develop repeatable configurations, validation procedures, automation, and infrastructure-as-code practices.

• Maintain accurate diagrams, configurations, interface definitions, operating procedures, and change records.

• Participate in change management, incident response, root-cause analysis, and corrective-action planning.

• Collaborate with systems, network, cybersecurity, and operations teams.

• Evaluate technologies based on standards compliance, interoperability, lifecycle cost, supportability, and mission suitability.

• Design and implement network automation that standardizes configuration, testing, deployment, monitoring, and compliance while reducing human error and accelerating the delivery of reliable network services.

• Support design and integration of video teleconferencing (VTC) and conference room AV capability across all program sites, including classified and unclassified variants.

• Support network and security operations center (NOC/SOC) functions, including monitoring tools, coverage models, and 24x7 support where required.

FOUNDATIONAL SKILLS

• Network models, packet flow, encapsulation, and protocol behavior.

• IPv4 and IPv6 addressing, subnetting, name resolution, and address-management principles.

• Layer 2 and Layer 3 networking, routing, switching, and segmentation.

• Transport protocols, application traffic patterns, and quality-of-service principles.

• Network security, encryption, access control, secure remote access, and traffic inspection.

• Wide-area, datacenter, cloud, and software-defined networking concepts.

• High availability, redundancy, load distribution, and failure-domain design.

• Network monitoring, telemetry, logging, packet analysis, and performance engineering.

• Scripting, automation, version control, and configuration-management fundamentals.

• Structured troubleshooting and root-cause analysis.

Location: This position is based in the Washington, DC metro area, with travel to program locations.

Travel: This position requires approximately 25-50% travel to support activities across multiple program locations.

Required:

• Bachelor's degree in a related field or equivalent experience.

• 5+ years of network engineering experience, including in classified environments.

• Working knowledge of routing, switching, and network security fundamentals.

• Relevant certification (e.g., CCNA, CCNP, Security+).

• Familiarity with ICD 705 physical security standards for SCIF design and accreditation.

• Familiarity with the Risk Management Framework (RMF) per NIST SP 800-37 and NIST SP 800-53 for system security authorization.

Nice to Have:

• Experience supporting cross-domain or multi-level security network solutions.

• Experience deploying networks in newly constructed or renovated facilities.

• Demonstrated experience leading or supporting large, geographically dispersed teams.

• Experience supporting Special Access Program (SAP) facilities, systems, or environments.