Network System Administrator with Security Clearance

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.

Key Responsibilities Network Administration & Engineering
* 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. Infrastructure & Virtualization Management
* 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. Security, Compliance & Access Control
* 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. Desktop Support & IT Lifecycle Management
* 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.

Required Qualifications
* 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.

Preferred Qualifications
* Experience leading teams through the design, implementation, and optimization of mission-critical enterprise environments.
* Cisco

Certifications:

CCNA or CCNP.
* Additional CompTIA

Certifications:

Network+, Server+.
* Microsoft or Linux

Certifications:

Azure, Windows Server Hybrid Administrator, or RHCSA.
* Familiarity with security best practices and regulatory compliance frameworks (e.g., HIPAA, PCI, SOC 2, RMF).
* Strong background in provisioning, maintaining, and troubleshooting complex networks.
* Understanding of Risk Management Framework (RMF), STIG applications, and operating within highly regulated government IT environments.
* Experience with Splunk, Big Fix, Fortinet, SharePoint.
* Experience in a leadership role Compensation Details:
$120K-$150K The compensation range or hourly rate listed for this position is provided as a good-faith…