Senior Network Administrator - TS/SCI with Polygraph

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.   

HOW A NETWORK ADMINISTRATOR WILL MAKE AN IMPACT:  

• 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 EtherChannel/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 DoW/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. 

 WHAT YOU’LL NEED TO SUCCEED:  

• 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-Site required 

• Strong knowledge of OSPF, RIP, and BGP routing protocols (Layer 3) 

• 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 EtherChannel/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 DoW/DISA STIGs and security baseline enforcement 

• Ability to work independently and drive tasks to completion with minimal supervision