Senior Network Administrator - TS​/SCI with Polygraph

Type of Requisition:

Regular

Clearance Level Must Currently Possess:

Top Secret/SCI

Clearance Level Must Be Able to Obtain:

Top Secret SCI + Polygraph

Public Trust/Other

Required:

None

Job Family:

IT Infrastructure and Operations

Skills:

Network Infrastructures, Networking Hardware, Network Systems

Certifications:

None

Experience:

6 + years of related experience US Citizenship

Required:

Yes

Transform technology into opportunity a Network Computer Systems Administrator with GDIT. A career in enterprise IT means connecting and enhancing the systems that matter most. At GDIT you’ll be at the forefront of innovation and play a meaningful part in improving how agencies operate. At GDIT, people are our differentiator. As a Network Computer Systems Administrator, you will help ensure today is safe and tomorrow is smarter.

• Install, configure, and maintain enterprise LAN/WAN infrastructure, including routers, switches, firewalls, and VPNs.
• Independently design and build new network environments, including topology, configuration, and architecture planning.
• Configure and troubleshoot dynamic routing protocols, including OSPF, RIP, and BGP.
• Configure and apply standard ACLs to enforce security and traffic policies.
• Configure, maintain, and troubleshoot Cisco/Juniper enterprise switching environments (Catalyst, Nexus, EX, QFX).
• Design and implement VLANs, trunking (802.1Q), and inter-VLAN routing to support multi-tenant and segmented environments.
• Manage Spanning Tree Protocol (STP, RSTP, MST) to ensure loop-free topology and rapid convergence.
• Deploy Ether Channel/LACP for link redundancy and throughput optimization.
• Administer, configure, and manage Cisco ASA appliances, including VPN solutions and secure remote access.
• Implement and manage firewall platforms (Cisco ASA/Firepower, Palo Alto, Juniper SRX) with strong experience in rule creation, policy management, and security hardening.
• Enforce DoD/DISA STIGs and security baselines across network infrastructure.
• Monitor, optimize, and troubleshoot network performance to ensure high availability, reliability, and security.
• Provide advanced troubleshooting and root cause analysis for complex connectivity issues.
• Support network modeling, analysis, and capacity planning to align with modernization initiatives.
• Collaborate with engineering teams on integration of emerging technologies and network upgrades.
• Provide mentorship or guidance to user support and network support staff as required.

• Required
  
  Education and Experience:
  
  Technical Training, Certification(s) or Degree + 8 years
• Certifications:
  
  DoD Manual 8570.01-M at the Information Assurance Technical (lAT) Level II role& Cisco Certified Network Associate (CCNA) minimum requirement;
  Cisco Certified Network Professional (CCNP) preferred.
• Security Clearance Level: Active TS/SCI with Polygraph
• Location:
  
  100% On-Siterequired
• Strong knowledge of OSPF, RIP, and BGP routing protocols (Layer3)
• Knowledge of standard ACLs for security and traffic filtering
• Strong knowledge of Cisco routing and switching technologies
• Configure, maintain, and troubleshoot enterprise Layer 2 switching (Catalyst, Nexus, EX, QFX)
• VLAN design, trunking (802.1Q), inter-VLAN routing, and STP/RSTP/MST management
• Experience with Ether Channel/LACP for redundancy and performance
• Ability to configure and manage Cisco ASA appliances
• Knowledge of VPN technologies, secure remote access, and remote administration
• Knowledge of network architecture planning and design
• Familiarity with DoD/DISA STIGs and security baseline enforcement
• Ability to work independently and drive tasks to completion with minimal supervision

At GDIT, the mission is our purpose, and our people are at the center of everything we do.

• Growth: AI-powered career tool that identifies career steps and learning opportunities
• Support:
  An internal mobility team focused on helping you achieve your career goals
• Rewards:
  Comprehensive benefits and wellness packages, 401K with company match, and competitive pay and paid time off
• Community:
  Award-winning culture of innovation and a military-friendly workplace

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