Network System Administrator

General information

Requisition #

R68342

Locations

USA-CA-El Segundo

Posting Date

06/04/2026

Security Clearance Required

TS/SCI

Remote Type

Onsite

Time Type

Full time

Description & Requirements

Shape the future of defense with MANTECH! Join a team dedicated to safeguarding our nation through advanced tech and innovative solutions. Since 1968, we've been a trusted partner to the Department of Defense, delivering cutting-edge projects that make a real impact. Dive into exciting opportunities in Cybersecurity, IT, Data Analytics and more. Propel your career forward and be part of something extraordinary. Your journey starts now-protect and innovate with MANTECH!

MANTECH seeks a motivated, career and customer-oriented Network/System Administrator (NSA) -III to join our team in El Segundo, CA.

The Network/System Administrator (NSA) -III will leverage their strong technical background and knowledge to support Special Access Programs (SAPs) and other classified networks supporting SSC Directorates and/or AFSPC Operational Units. This role supports day-to-day operations for Collateral, Sensitive Compartmented Information (SCI), and Special Access Program (SAP) activities in a five-day-a-week, in-office environment.

Responsibilities include but are not limited to:

• Install, maintain, audit, and support a secure MS Windows network environment, file servers, firewalls, and network access while troubleshooting anomalies to ensure optimum performance.
• Maintain internet applications and protocols including IP, TCP, HTTP, HTTPS, FTP, and SSL.
• Interface directly with local customers and IT staff to provide technical guidance and quickly resolve network or desktop support issues.
• Perform periodic system maintenance, hardware upgrades and replacements, firmware updates, and system configuration changes.
• Manage the scheduled data backup library, including executing tape backups and arranging safe storage at customer locations or off-site facilities.
• Prepare systems for operational use, support operational tests, and attend planning and requirements meetings with program managers and stakeholders.
• Must meet position and certification requirements outlined in DoD Directive 8570.01-M for Information Assurance Technician Level 2 (IAT Level II) within 6 months of hire (e.g., Security+ CE, CCNA, CySA+, CND).

Minimum Qualifications:

• Bachelor's degree in a related technical area; an additional 4 years of related experience might be substituted for a degree.
• 6+ years of total related experience
• 4+ years of relevant SCI or SAP experience.

Preferred Qualifications:

• Thorough knowledge of Microsoft Windows Server (2000/2003/2007), Microsoft Exchange Server 2003, and Windows XP/Vista operating systems administration and associated hardware.
• Applicable Windows professional certifications based on OS requirements for the supported organization.
• Working knowledge of Local Area Network (LAN) and Wide Area Network (WAN) technologies, data backup systems, and communication security (COMSEC) integration.
• Working knowledge of JAFAN 6/0, DCID/JAFAN 6/3, DCID/JAFAN 6/9, and Joint DODIIS/Cryptologic SCI Information Systems Security Standards, Common Criteria, and System Security Policy as they relate to C&A for legacy systems.
• Experience with PL1 & PL2 systems, familiarity with PL3 & PL4 cross-domain solutions, and deep familiarity with security policies, manual ICDs, JAFANs, and DoD Manuals.

Clearance Requirements:

• An active Top Secret clearance with SCI eligibility is required to start.
• Applicants must be eligible for access to Special Access Programs (SAPs).
• Must have a willingness to submit to a Counterintelligence polygraph examination.

Travel:

This role requires regular travel within the organizational Area of Responsibility, which may include both air and ground transportation.

Physical Requirements:

• Must be able to remain in a stationary position 50% of the time in closed-area offices.
• Must be able to lift up to 50 pounds.
• Need to occasionally move about inside and outside the office to access files, cabinets, or safes, and to install or remove computer-related equipment.

The projected compensation range for this position is $107,900.00-$179,400.00. There are differentiating factors that can impact a final salary/hourly rate, including, but not limited to, Contract Wage Determination, relevant work experience, skills and competencies that align to the specified role, geographic location (For Remote Opportunities), education and certifications as well as Federal Government Contract Labor categories. In addition, MANTECH invests in its employees beyond just compensation. MANTECH's benefits offerings include, dependent upon position, Health Insurance, Life Insurance, Paid Time Off, Holiday Pay, short-term and long-term Disability, Retirement and Savings, Learning and Development opportunities, wellness programs as well as other optional benefit elections.

MANTECH considers all qualified applicants for employment without regard to disability or veteran status or any other status protected under any federal, state, or local law or regulation.

If you need a reasonable accommodation to apply for a position with MANTECH, please email us at careers@mantech.com and provide your name and contact information.