> Markdown version of [/jobs/ext/1975635-senior-network-administrator-ts-sci-with-polygraph](https://www.wearedevelopers.com/jobs/ext/1975635-senior-network-administrator-ts-sci-with-polygraph). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Network Administrator - TS/SCI with Polygraph - **Company:** General Dynamics Information Technology - **Location:** Washington, DC, United States - **Experience:** Expert - **Salary:** $124,093.0 - $161,000.0 - **Contract:** Permanent contract - **Skills:** IEEE 802.1Q, Link Aggregation (Ethernet), Border Gateway Protocol, Spanning Tree Protocols, Catalyst (Software), Cisco PIX, EtherChannel, Trunking, Networking Hardware, Virtual Private Networks (VPN), Network Layer, Network Architecture, Cisco Nexus Switches, Open Shortest Path First (OSPF), Remote Access Technology, Remote Administration, Virtual Local Area Networks, Wide Area Networks, Network Routers, Dynamic Routing, Computer Networking Systems, System Availability, Firewalls (Computer Science), Juniper, Build Management, Information Technology, Network Support, Palo Alto Networks, CIS Benchmarks, Firepower, Cisco - **Published:** August 7, 2026 - **Apply:** https://dejobs.org/x/x/C9201F6A6B95470CBD01A195CDD967B7/job/ ## About the Role Network Infrastructures,Networking Hardware,Network Systems, 6 + years of related experience, * 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 DoD/DISA STIGs and security baseline enforcement * Ability to work independently and drive tasks to completion with minimalsupervision ## Description 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 PROJECT MANAGER 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 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. ## Related Videos - [How Cisco embraced a DevOps culture within its network engineering team](https://www.wearedevelopers.com/videos/99-how-cisco-embraced-a-devops-culture-within-its-network-engineering-team) - [Trunk-Based Development at Scale: Real-World Insights from a High-Traffic Luxury E-Commerce Platform](https://www.wearedevelopers.com/videos/1435-trunk-based-development-at-scale-real-world-insights-from-a-high-traffic-luxury-e-commerce-platform) - [Your Infrastructure Is Not a Playground: AI Agents for Infra Done Right](https://www.wearedevelopers.com/videos/2084-your-infrastructure-is-not-a-playground-ai-agents-for-infra-done-right) - [Small, Secure, Interconnected: The next Internet Protocol](https://www.wearedevelopers.com/videos/100062-small-secure-interconnected-the-next-internet-protocol) - [100 times more frequent deployments: How did we create a high performance team?](https://www.wearedevelopers.com/videos/1069-100-times-more-frequent-deployments-how-did-we-create-a-high-performance-team) - [Computer Vision from the Edge to the Cloud done easy](https://www.wearedevelopers.com/videos/263-computer-vision-from-the-edge-to-the-cloud-done-easy) ## Related Articles - [Best Paying Jobs in Technology](https://www.wearedevelopers.com/magazine/256-best-paying-jobs-in-technology) - [Dev Digest 134 - Where pixels sing?](https://www.wearedevelopers.com/magazine/477-dev-digest-134-where-pixels-sing) - [Highest Paying Tech Companies for Developers](https://www.wearedevelopers.com/magazine/220-highest-paying-tech-companies-for-developers) - [Everything a Developer Needs to Know About MCP with Neo4j](https://www.wearedevelopers.com/magazine/604-everything-a-developer-needs-to-know-about-mcp-with-neo4j) - [What Are The Top Skills Required For Azure Developers?](https://www.wearedevelopers.com/magazine/77-what-are-the-top-skills-required-for-azure-developers) - [A Guide to Green Tech and Green IT Careers](https://www.wearedevelopers.com/magazine/374-a-guide-to-green-tech-and-green-it-careers)