Network Security Specialist

All hired employees are expected to have experience with Microsoft Copilot and / or an approved equivalent AI solution. Description Data Systems Analysts, Inc. (DSA) is seeking a TS/SCI cleared Network Security Specialist to secure, engineer, and defend enterprise network systems in a secure DoD environment. The Network Security Specialist will perform hands-on security configuration, boundary defense engineering, vulnerability remediation, and device hardening for Cisco based network infrastructure. The Network Security Specialist will work closely with network engineers, cybersecurity staff, security administrators, and mission partners to ensure network systems remain secure, hardened, resilient, and operationally effective. This role is suited for a highly technical security professional with hands-on experience in Cisco network infrastructure, firewall management, ports and protocols, packet-level analysis, and active network defense. This position is onsite in Charlottesville, VA. Responsibilities Configure and review firewall rules, access control lists, ports, protocols, services, VPN connections, network flows, and boundary protection controls. Configure, validate, and audit security configurations for Cisco routers, switches, firewalls, and related network infrastructure. Support active network security operations, boundary defense engineering, and continuous hardening for enterprise network systems. Support incident response activities by performing technical analysis of network related alerts, logs, firewall events, syslog data, and authentication events. Support change control reviews by assessing proposed network changes for cybersecurity impacts, configuration vulnerabilities, and security architecture alignment. Monitor network security posture through syslog alerts, configuration management tools, and packet-level analysis. Conduct, analyze, and remediate vulnerability scans using ACAS, Tenable Nessus, STIG Viewer, and other approved DoD tools. Analyze vulnerability findings, identify false positives, engineer technical workarounds, and execute remediation actions across network devices. Implement and validate DISA STIG compliance, SCAP benchmarks, security baselines, and device hardening requirements. Develop and maintain technical network security documentation including device hardening procedures, network diagrams, and Ports, Protocols, and Services (PPS) listings. Support technical engineering assessments and security reviews to maintain authorization sustainment activities. Prepare technical security status updates, vulnerability remediation roadmaps, and network security risk briefings for engineering teams and stakeholders. Required Education, Certifications and Security Clearance BS degree in Engineering, Computer Science, or related field Experience may be substituted for degree. TS/SCI Clearance DoD 8140 (8570) IAT Level II Certification CCNA certification Requirements Experience/Qualifications Minimum 4 years of experience supporting network security engineering, secure network operations, boundary defense, or hands-on network administration. Working knowledge of Cisco routers, switches, firewalls, Cisco ASA, Cisco Firepower, Cisco Secure Firewall, Cisco ISE, Catalyst, Nexus, ISR, or ASR platforms. Working knowledge of routing, switching, VLANs, ACLs, firewall policies, ports, protocols, VPNs, IPsec, NAT, DNS, DHCP, subnetting, logging, and boundary protection. Ability to design and review network diagrams, firewall rule sets, data flows, ports and protocols, and system interconnections for security vulnerabilities. Demonstrated understanding of network hardening practices, secure protocols, network security architecture, and boundary defense concepts. Experience coordinating with network engineers, systems administrators, security analysts, and mission partners to resolve technical security findings. Hands on experience with ACAS, Tenable Nessus, STIG Viewer, SCAP, and network vulnerability remed…