Network Security Engineer, Lead; Top Secret Clearance SCI & SAP eligibility

AMERICAN SYSTEMS, a 100% employee-owned federal government contractor
, is seeking a Lead Network Security Engineer to support a critical national security mission in a highly classified environment in Dallas, TX
. This position requires the ability to work independently in a complex, security-focused environment.

We’re seeking an experienced network professional with strong hands‑on experience in enterprise networking, network security, firewall administration, and infrastructure troubleshooting
. Experience administering and troubleshooting enterprise firewall technologies is required
, including platforms such as Cisco Firepower, Firepower Management Center, Palo Alto, Fortinet, Check Point, or similar solutions
.

Experience with
Cisco ISE, network access control, authentication, authorization, or 802.1X is also valued.

As a Lead Network Security Engineer
, you will:

• Lead secure network engineering, administration, and operational support in a highly classified environment.
• Design, implement, configure, and maintain enterprise network infrastructure
  , including:
  • Routers and switches |
    Firewalls |
    VLANs |
    ACLs |
    VPNs
  • Network segmentation |
    High-availability architectures
• Administer, monitor, and troubleshoot enterprise firewall environments
  .
• Configure and manage firewall policies, access rules, NAT, VPNs, security zones, logging, and monitoring
  .
• Support and troubleshoot Cisco Firepower and Firepower Management Center (FMC). Cisco Firepower experience is preferred.
• Troubleshoot complex Layer 2 and Layer 3 networking
  , routing, switching, firewall, connectivity, and access control issues.
• Support AAA, authentication, authorization, accounting, and network access control requirements.
• Configure and troubleshoot 802.1X, VPN, and network access control solutions
  .
• Support Cisco ISE environments, including authentication, authorization, policy enforcement, and network access control. Cisco ISE experience is preferred.
• Support RMF, STIG, secure configuration, vulnerability remediation, and compliance activities
  .
• Develop and maintain network diagrams, implementation plans, SOPs, configuration documentation, and technical reports
  .
• Partner with cybersecurity, systems administration, and mission teams to deliver secure and resilient network solutions.
• Support incident response, outage resolution, root cause analysis, change implementation, and network remediation efforts.
• Monitor network performance and recommend improvements to strengthen security, availability, reliability, and performance
  .
• Provide technical leadership and guidance to network engineering and operations personnel.

• U.S. citizenship required.
• Active TS/SCI clearance with SAP eligibility required.
• Bachelor’s degree in a related technical field, or additional relevant experience in lieu of a degree.
• Eight or more years of experience in network engineering, network operations, or network security.
• Experience working in enterprise, defense, intelligence, federal government, or highly regulated environments
  .
• Strong hands‑on experience with enterprise networking
  , including:
• • Routing and switching |
    Layer 2 and Layer 3 troubleshooting |
    VLANs and subnetting
  • Access control lists, or ACLs |
    Network addressing and design |
    VPN technologies
  • Network segmentation |
    Resilient network architectures
• Hands‑on experience administering and troubleshooting enterprise firewalls
  .
• Experience with one or more of the following firewall platforms:
  • Cisco Firepower and FMC preferred |
    Palo Alto Networks |
    Fortinet |
    Check Point
  • Other commercial or government enterprise firewall platforms
• Experience with firewall policy administration, rule management, NAT, VPNs, security zones, logging, monitoring, and troubleshooting
  .
• Experience supporting AAA, 802.1X, RMF, STIG,…