Senior Network Administrator - Mission-Critical Security

Koitecc Solutions; Gaithersburg (MD); On-site; USD 92,000 - 167,000; Full time

Job summary

Leidos in Gaithersburg, MD is seeking a Senior Network Administrator to lead enterprise network infrastructure, ensure security, and support agile teams in delivering mission-critical capabilities for the Intelligence Community.

The role requires active Top Secret/SCI clearance with polygraph, CCNA or CCNP, Security+ and DoD 8140/8570 IAM compliance, and hands-on experience with Cisco routing, switching, and firewalls; familiarity with cloud networking and SDN is a plus.

Qualifications

• US citizenship required per contract.
• Bachelor’s degree in Computer Science, Engineering, Information Technology or related field with 8–12 years of prior relevant experience or Master’s with 6–10 years of prior relevant experience.
• 8+ years of network administration experience.
• DoD 8140/8570 Compliance: Must possess an active CompTIA Security+ (or higher baseline certification) to satisfy IAM Level I / IAT Level II requirements.
• Cisco Networking: Must possess an active Cisco Certified Network Associate (CCNA) or Cisco Certified Network Professional (CCNP) Enterprise certification.
• Experience supporting large‑scale, mission‑critical network environments.
• Strong expertise with Cisco routing and switching technologies.
• Thorough understanding of: TCP/IP, OSPF, BGP, EIGRP, VLANs, DNS/DHCP, VPN technologies, NAT, QoS, Multicast.
• Experience administering enterprise firewalls such as Cisco ASA, Palo Alto, or Fortinet.
• Experience with network monitoring and performance management tools.
• Strong troubleshooting, analytical, and problem‑solving skills.
• Excellent communication skills and the ability to collaborate across technical disciplines.
• Experience working in Agile or Scrum environments.

Responsibilities

• Design, configure, administer, and maintain complex enterprise LAN, WAN, WLAN, VPN, and data center network environments.
• Install, configure, and support Cisco routers, switches, firewalls, load balancers, and other network infrastructure components.
• Collaborate with Agile Scrum teams to deliver infrastructure enhancements supporting continuous integration and rapid capability delivery.
• Participate in sprint planning, backlog refinement, daily stand‑ups, reviews, and retrospectives as the networking subject matter expert.
• Monitor network performance, capacity, and availability while proactively identifying opportunities for optimization.
• Troubleshoot complex network issues, perform root cause analysis, and implement long‑term corrective actions.
• Implement and maintain secure network architectures in accordance with Intelligence Community security requirements and best practices.
• Support cloud connectivity, hybrid networking, and infrastructure modernization initiatives.
• Develop and maintain network documentation, topology diagrams, standard operating procedures, and configuration baselines.
• Coordinate hardware refreshes, software upgrades, maintenance windows, and patch management activities.
• Partner with cybersecurity teams to address vulnerabilities, implement security controls, and support audits and accreditation activities.

Skills

Network administration

Troubleshooting

Communication

Agile/Scrum

Analytical thinking

Education

Bachelor's degree in CS/Engineering/IT

Master’s degree

Tools

Cisco IOS

Palo Alto

Fortinet

AWS

Azure

VMware NSX

Job description

Leidos in Gaithersburg, MD is seeking a Senior Network Administrator to lead enterprise network infrastructure, ensure security, and support agile teams in delivering mission-critical capabilities for the Intelligence Community.

The role requires active Top Secret/SCI clearance with polygraph, CCNA or CCNP, Security+ and DoD 8140/8570 IAM compliance, and hands-on experience with Cisco routing, switching, and firewalls; familiarity with cloud networking and SDN is a plus.