Linux and Windows Systems Administrator

Koitecc Solutions; Beavercreek (OH); On-site; USD 69,550 - 125,725; Full time

Job summary

Koitecc Solutions is seeking a Linux and Windows System Administrator to maintain and secure classified environments in Beavercreek, OH. The role includes administering Windows and Linux systems, incident resolution, and ensuring system compliance.

Qualified candidates must possess an active DoD Secret clearance and relevant experience in system administration and security practices. The pay range for this position is set between $69,550.00 and $125,725.00.

Qualifications

• Active DoD Secret security clearance is required.
• CompTIA Security+ certification is mandatory.
• Experience in secure or air-gapped environments is essential.

Responsibilities

• Administer Windows and Linux systems across multiple environments.
• Perform troubleshooting and root-cause analysis for technical issues.
• Manage system patching and compliance activities.

Skills

Windows Server administration

Linux systems administration (RHEL, Rocky Linux, Ubuntu)

PowerShell scripting

Bash scripting

Active Directory management

Network troubleshooting

Education

Bachelor's degree in a technical field with 2-4 years of experience

Tools

VMware

Hyper-V

Ansible

Tenable Nessus

Job description

Leidos Corporate Information Security Office (CISO), reporting through the Digital sector, is seeking a Linux and Windows System Administrator to support and maintain complex classified environments. The selected candidate will be responsible for administering, securing, troubleshooting, and maintaining Windows and Linux systems across physical and virtual infrastructures. This role supports mission-critical operations by ensuring system availability, compliance with security requirements, and reliable day-to-day operations within a secure enterprise environment.

Location: All work will be performed onsite in our Beavercreek, OH office.

Clearance: You must currently carry an active DoD Secret clearance to qualify for consideration.

Primary Responsibilities

• Administer and maintain Windows Workstations, Windows Server, and Linux systems (RHEL, Rocky Linux, Ubuntu) across physical, virtual, and air-gapped environments.
• Perform Tier 2 incident resolution, troubleshoot technical issues, conduct root-cause analysis, and collaborate with engineering, cybersecurity, and stakeholders to resolve complex problems.
• Execute system patching, vulnerability remediation, configuration management, and compliance activities.
• Implement and maintain monitoring, logging, backup and recovery solutions, and operational documentation/runbooks.
• Support account and access administration in accordance with least-privilege principles and organizational security policies.
• Automate repetitive administrative tasks using PowerShell, Bash, Ansible, or similar automation tools.
• Deploy and maintain operating system images using PXE/network boot, Kickstart, disk imaging, answer files, and automated installation methods.
• Perform system hardening and security compliance using DISA STIGs, SCAP, and NIST 800-53 security controls.
• Administer and troubleshoot Active Directory, DNS, DHCP, file servers, virtualization platforms, and Layer 2 network switching, including VLAN configuration, TCP/IP connectivity, and switch port administration in an air-gapped environment.
• Support dual-boot bare-metal systems and virtualized environments.
• Participate in after-hours support and on-call rotations as required.
• Research, analyze, and resolve Windows, Linux, and networking issues to maintain system availability, reliability, and performance.

Basic Qualifications

• Current Active DoD Secret security clearance.
• Current CompTIA Security+ certification.
• Bachelor's degree in a technical field with 2-4 years of relevant experience. Additional years of experience may be considered in lieu of a degree.
• Experience administering Windows Server and Linux systems in secure or air-gapped environments.
• Experience implementing DISA STIGs, SCAP, NIST 800-53 security controls, and system hardening practices.
• Experience administering:
  • Active Directory
  • DNS
  • DHCP
  • File Servers
• Experience building, integrating, maintaining, troubleshooting, and remediating Windows and Linux systems.
• Experience deploying operating systems using PXE, Kickstart, ISO/disk imaging, and automated installation methods.
• Experience configuring and troubleshooting Layer 2 switching, VLANs, TCP/IP, and network connectivity.
• Experience managing Windows and Linux updates, patching, and vulnerability remediation.
• Ability to develop automation scripts using PowerShell and Bash.
• Familiarity with Linux software repository management.
• Ability to work independently and collaboratively with minimal supervision.
• Strong analytical, communication, and problem-solving skills.

Preferred Qualifications

• Red Hat Certified System Administrator (RHCSA) certification.
• Experience administering VMware, Hyper-V, or other virtualized environments.
• Experience with automation and configuration management tools, including Ansible.
• Experience supporting secure or classified DoD environments.
• Knowledge of backup, recovery, logging, and monitoring solutions.
• Experience performing DISA STIG remediation, SCAP compliance validation, and vulnerability scanning using Tenable Nessus.

Pay Range

$69,550.00 - $125,725.00

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.