Senior Network Engineer

Leidos is seeking a Senior Network Engineer to support the design, implementation, modernization, and sustainment of enterprise network infrastructure within a fast-paced Department of Defense (DoD) environment in Fort Belvoir, VA or Albuquerque, New Mexico. The successful candidate will provide engineering expertise for mission-critical Local Area Network (LAN), Wide Area Network (WAN), and secure network infrastructure supporting classified and enterprise operations. The ideal candidate is an experienced network engineer with extensive knowledge of Cisco networking technologies, Palo Alto Networks security solutions, and enterprise routing and switching. This individual will work independently and collaboratively with multidisciplinary engineering teams to deliver secure, resilient, and scalable network solutions that support evolving customer mission requirements. Clearance: Active TS/SCI clearance at time of hire. Primary Responsibilities: * Design, implement, configure, and maintain enterprise LAN and WAN infrastructure. * Engineer and support Cisco routing and switching environments for mission-critical networks. * Configure, troubleshoot, and optimize enterprise routing and switching technologies, including:

* OSPF

* BGP

• VLANs
• Spanning Tree Protocol (STP)

* HSRP/VRRP

* Support WAN connectivity utilizing MPLS, VPN, and Internet-based transport technologies. * Configure, administer, and maintain Palo Alto Networks next-generation firewalls. * Design, implement, and support secure Palo Alto GlobalProtect remote access and site-to-site VPN solutions. * Monitor network health, analyze performance, identify bottlenecks, and implement corrective actions. * Perform advanced Layer 1–7 network troubleshooting using industry-standard diagnostic tools. * Develop and maintain engineering documentation, implementation plans, network diagrams, and standard operating procedures. * Participate in technology refreshes, network modernization efforts, and infrastructure upgrades. * Collaborate with cybersecurity personnel to ensure compliance with DoD cybersecurity policies, RMF requirements, and applicable STIGs. * Support scheduled maintenance activities, incident response, and operational troubleshooting in a high-availability environment. Basic Qualifications: * Bachelor’s degree in computer science, information technology, engineering, or a related discipline with 8+ years of relevant experience. Additional years of experience may be substituted for a degree. * Active DoD 8570/8140 IAT Level II certification (Security+, CySA+, or equivalent).

• Active Cisco Certified Network Associate (CCNA) certification.
• Active TS/SCI clearance at time of hire.
• Extensive experience designing, implementing, and supporting enterprise Cisco

network infrastructure. * Strong working knowledge of:

* TCP/IP

* IPv4/IPv6

* DDI (DNS / DHCP / IPAM)

* NAT

• VLANs
• Copper and fiber optic cabling standards
• Quality of Service (QoS)

* OSPF

* MPLS

• Secure Access Service Edge (SASE) technologies
• Hands-on experience configuring and administering Palo Alto Networks

next-generation firewalls, including security policies, NAT, threat prevention, and GlobalProtect. * Experience implementing and supporting secure remote-access and site-to-site VPN technologies.

• Demonstrated experience troubleshooting enterprise LAN and WAN environments.
• Experience supporting networking solutions within a fast-paced Department of

Defense enterprise.

• Excellent written, verbal, and interpersonal communication skills.
• Ability to manage multiple priorities while working independently and as part

of a technical team. Preferred Qualifications:

• Cisco Certified Network Professional (CCNP) certification.
• Experience with Border Gateway Protocol (BGP) and advanced Software-Defined

WAN (SD-WAN) architectures. * Experience deploying and supporting Versa Networks or similar SD-WAN solutions. * Experience with network automation using Python, Ansible, and Infrastructure-as-Code (IAC) technologies. * Familiarity with Network Access Control and Comply-to-Connect technologies such as Cisco Identity Services Engine (ISE) and IEEE 802.1X authentication. * Experience with enterprise network monitoring platforms such as SolarWinds or

PRTG.

* Experience supporting hybrid cloud networking in Microsoft Azure and/or AWS environments. * Knowledge of DoD Risk Management Framework (RMF), Security Technical Implementation Guides (STIGs), and Zero Trust networking principles including SD-WAN, micro- and macro-segmentation, and Zero Trust Network Access (ZTNA). * Familiarity with break-and-inspect, reverse-web-proxy, and other application-based firewall features. * Experience reviewing packet capture data for troubleshooting and packet analysis. * Experience supporting on-prem virtualization platforms such as vSphere. If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

ORIGINAL POSTING:

July 28, 2026 For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

PAY RANGE:

Pay Range $92,300.00 - $166,850.00 The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.