Senior Network Administrator - TS/SCI with Polygraph

Network Computer Systems AdministratorTransform technology into opportunity with GDIT. A career in enterprise IT means connecting and enhancing the systems that matter most. 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.What You'll Need to Succeed:Required Education and Experience: Technical Training, Certification(s) or Degree + 8 yearsCertifications: DoD Manual -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 PolygraphLocation: 100% On-Site requiredStrong knowledge of OSPF, RIP, and BGP routing protocols (Layer 3)Knowledge of standard ACLs for security and traffic filteringStrong knowledge of Cisco routing and switching technologiesConfigure, maintain, and troubleshoot enterprise Layer 2 switching (Catalyst, Nexus, EX, QFX)VLAN design, trunking (802.1Q), inter-VLAN routing, and STP/RSTP/MST managementExperience with EtherChannel/LACP for redundancy and performanceAbility to configure and manage Cisco ASA appliancesKnowledge of VPN technologies, secure remote access, and remote administrationKnowledge of network architecture planning and designFamiliarity with DoW/DISA STIGs and security baseline enforcementAbility to work independently and drive tasks to completion with minimal supervisionGDIT IS YOUR PLACE 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 workplaceThe likely salary range for this position is $124,093 - $161,000. This is not, however, a guarantee of compensation or salary. Rather, salary will be set based on experience, geographic location and possibly contractual requirements and could fall outside of this range.Scheduled Weekly Hours: 40Travel Required: NoneTelecommuting Options: OnsiteWork Location: USA DC WashingtonAdditional Work Locations:Total Rewards at GDIT: Our benefits package for all US-based employees includes a variety of medical plan options, some with Health Savings Accounts, dental plan options, a vision plan, and a 401(k) plan offering the ability to contribute both pre and post-tax dollars up to the IRS annual limits and receive a company match. To encourage work/life balance, GDIT offers employees full flex work weeks where possible and a variety of paid time off plans, including vacation, sick and personal time, holidays, paid parental, military, bereavement and jury duty leave. To ensure our employees are able to protect their income, other offerings such as short and long-term disability benefits, life, accidental death and dismemberment, personal accident, critical illness and business travel and accident insurance are provided or available. We regularly review our Total Rewards package to ensure our offerings are competitive and reflect what our employees have told us they value most.Our Identity Verification Process: As part of the hiring process, we will ask you to complete an identity verification process that leverages advanced biometrics and artificial intelligence to ensure authenticity and protect against identity fraud. You are expected to be on camera during virtual interviews. We reserve the right to take your picture to verify your identity and prevent fraud. By proceeding, you authorize the collection, processing, and use of your biometric data for identity verification and security purposes.About Our Work: We are GDIT. A global technology and professional services company that delivers technology solutions and mission services to every major agency across the U.S. government, defense and intelligence community. Our 26,000 experts extract the power of technology to create immediate value and deliver solutions at the edge of innovation. We operate across 50+ countries worldwide, offering leading mission-ready capabilities in AI, cloud, cyber and software development.