Systems Administrator

G2IT is seeking an experienced Tenable Administrator (Level 3) to support enterprise vulnerability management and cybersecurity operations within a DoD environment. The ideal candidate will have extensive hands‑on experience administering Tenable SecurityCenter, Nessus Scanner, Red Hat Enterprise Linux (RHEL), and enterprise vulnerability scanning solutions. Key Responsibilities Install, configure, administer, maintain, and troubleshoot Tenable SecurityCenter and Nessus Scanner environments. Develop, configure, test, and deploy enterprise-level vulnerability, compliance, and discovery scan policies. Schedule and maintain recurring vulnerability and compliance scans using Tenable solutions. Administer and maintain applications within Red Hat Enterprise Linux (RHEL) environments. Develop and troubleshoot Linux shell scripts used for system and application administration. Monitor and optimize Tenable infrastructure to ensure availability, performance, and security. Support vulnerability identification, assessment, reporting, and remediation activities. Apply Security Technical Implementation Guides (STIGs) to harden Linux operating systems. Support servers hosted within VMware, AWS, Azure, and other virtual or cloud environments. Support Public Key Infrastructure (PKI) requirements and secure system communications. Troubleshoot Tenable, Nessus, Linux, network, and application-related issues. Maintain technical documentation, configuration procedures, scan policies, and system administration records. Communicate vulnerability findings and technical issues effectively to technical teams, leadership, and mission stakeholders. Required Qualifications Must hold an active Top Secret (TS) security clearance and be eligible for TS/SCI access. 5–7 years of experience in information systems with a focus on application administration. 3–5 years of direct experience installing, maintaining, and administering Tenable SecurityCenter, Nessus Scanner, and related software components. 3–5 years of experience developing, configuring, and maintaining recurring discovery, compliance, and vulnerability scans using Tenable. 3–5 years of application administration and maintenance experience within a RHEL environment. Expert-level knowledge of installing and administering Tenable SecurityCenter in an enterprise environment. Experience developing, configuring, testing, and deploying enterprise-level scan policies. Strong experience with Red Hat Enterprise Linux (RHEL) and multiple RHEL OS releases. Experience developing and debugging Linux shell scripts. Experience hardening Linux systems using Security Technical Implementation Guides (STIGs). Working knowledge of VMware and cloud environments such as AWS and/or Azure. Working knowledge of Public Key Infrastructure (PKI). Strong troubleshooting and problem-solving skills. Effective written and verbal communication skills. Certification Requirements Must possess at least one Linux operating system administrator certification. #J-18808-Ljbffr