Network System Administrator

Amentum is seeking a highly motivated and skilled Network Systems Administrator to support NASA Headquarters. In this full-time, on-site role, you will be responsible for managing and securing an enterprise network infrastructure and mixed-server environment. This role supports the full lifecycle of IT systems, ensuring the availability, performance, security, and compliance of mission‑critical infrastructure. The ideal candidate will possess a strong primary background in network administration and engineering, coupled with robust systems administration experience across Windows, Linux, and Proxmox virtualization platforms.

The candidate should have experience leading cross‑functional teams from project conception through successful execution.

You will play a critical role in supporting diverse operations, managing COTS and GOTS hardware and software, and ensuring strict adherence to government cybersecurity policies.

• Administer and maintain complex LAN/WAN environments, including routers, switches, firewalls, VPNs, VLAN configurations, and network segmentation.
• Monitor network performance, troubleshoot connectivity issues, and implement configuration changes to ensure high availability and security.
• Maintain detailed documentation of network diagrams, configurations, system baselines, and operational procedures.

• Administer, maintain, and optimize Proxmox VE virtualization clusters to ensure high availability and resource efficiency.
• Manage Windows Server environments, including Active Directory, Group Policy, DNS, patch management, antivirus updates, and system upgrades.
• Deploy, configure, and manage Windows and Linux operating systems within virtualized and physical environments.
• Perform regular backups and disaster recovery validation to ensure data integrity across all server and storage environments.

• Configure, harden, and monitor network and system environments in accordance with government security standards (e.g., STIGs).
• Continuously monitor system logs, network traffic, and security alerts.
• Investigate, document, and report incidents, vulnerabilities, and threats.
• Collaborate with ISSO/ISSM and security staff to ensure all system changes comply with RMF (Risk Management Framework) and local security policies.

• Install, configure, and maintain Commercial Off-The-Shelf (COTS) and Government Off-The-Shelf (GOTS) software applications.
• Provide desktop support for Windows workstations, resolving complex user issues and deploying new hardware/software.
• Provide full lifecycle management of IT infrastructure, including procurement support, deployment, configuration management, and secure decommissioning of hardware and software assets.

• Must possess an active US Government Top Secret security clearance with the ability to obtain SCI and must consent to a CI Polygraph. Please note US Citizenship is required to maintain a Top Secret clearance.
• Must meet DoD 8570.01-M Information Assurance Technical (IAT) Level II certification requirements (e.g., CompTIA Security+ CE) prior to starting date.
• Associate degree or higher in Computer Science, Information Technology, Network Engineering, or a related field (or equivalent work experience) with at least 5 to 8 years of relevant IT experience.
• Networking:
  Expert knowledge of network protocols (TCP/IP, DNS, VLANs, VPNs), LAN/WAN management, routing, switching, and hands‑on experience with hardware firewalls and VPNs.
• Systems Administration:
  Proven experience with Windows Server, Active Directory, and Linux system administration.
• Virtualization:
  Hands‑on experience building and managing virtual machines using Proxmox VE.
• Automation:
  Ability to automate administrative tasks via scripting languages such as Power Shell, Bash, or Python.
• Desktop & Applications:
  Demonstrated ability to provide workstation support and deploy/troubleshoot COTS and GOTS applications.

• Experience leading teams through the design, implementation, and optimization of…