Network Engineer, Lead - Firewall Infrastructure | Top Secret w/SCI eligibility
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Before you apply
Salary$155k – $180k
LocationDallas, TX, US
Work modeon-site
Typefull-time
SeniorityLead
Experience8+ yrs
DepartmentIT / Cyber Security / Network Systems
Company size1,001–5,000 people
PostedOct 9, 2026 · 3w ago
Verified live15h ago
At a glanceSummarised by Seekless from the posting.
Active Top Secret clearance required, with eligibility to obtain SCI and SAP access
Bachelor’s degree in a related technical field, or additional relevant experience in lieu of a degree
8+ years of experience in network engineering, network operations, network infrastructure, or firewall administration
Active DoD 8140/8570 IAT Level II certification, e.g., Security+ CE, CySA+, SSCP, or equivalent
Active Cisco Certified Network Associate (CCNA) certification or higher-level Cisco networking certification
Strong hands-on experience with enterprise network infrastructure including routing and switching, Layer 2 and Layer 3 troubleshooting, VLANs, subnetting, IP addressing, network design, ACLs, VPN technologies, network segmentation, and resilient network architectures
Hands-on experience administering and troubleshooting enterprise firewall platforms
Experience with firewall policy administration, rule management, NAT, VPNs, security zones, logging, monitoring, and troubleshooting
Experience supporting AAA, 802.1X, network access control, RMF, STIG, and secure configuration requirements
Experience troubleshooting Cisco routers, switches, firewalls, and enterprise network infrastructure
Ability to work independently, lead technical efforts, and resolve complex network and firewall infrastructure issues
Strong written and verbal communication skills
Cisco ISE experience preferred, particularly with authentication, authorization, accounting, policy enforcement, and network access control
Cisco Firepower and Firepower Management Center (FMC) experience preferred
Experience supporting highly compartmented or special-access classified environments
Advanced Cisco networking certifications, such as CCNP Enterprise, CCNP Security, or CCIE
Experience with Palo Alto Networks, Fortinet, Check Point, or other enterprise firewall technologies
Experience with Cisco ISE, NAC, 802.1X, or related access control platforms
Experience supporting network modernization, infrastructure upgrades, technology refreshes, network migrations, or data center transformation efforts
Experience developing network diagrams, implementation plans, configuration documentation, and standard operating procedures
Experience with network change management, outage resolution, root cause analysis, and incident response in classified environments
Familiarity with VMware or other virtualized environments
U.S. citizenship required
Skills
Cisco Firepower
Firepower Management Center (FMC)
Cisco ISE
802.1X
VPN
VLAN
ACL
NAT
Palo Alto Networks
Fortinet
Check Point
VMware
Python
Cisco routers
Cisco switches
STIG
RMF
Benefits
Health insurance
Paid leave
Retirement plans
Insurance programs
Education assistance
Training assistance
Overview
AMERICAN SYSTEMS, a 100% employee-owned federal government contractor, is seeking a Lead Network Engineer, Firewall Infrastructure to support a critical national security mission in a highly classified environment in Dallas, TX.
This is a hands-on network engineering role focused on enterprise firewall infrastructure, routing and switching, secure connectivity, and network access control. The selected candidate will lead the configuration, administration, troubleshooting, and operational support of a complex enterprise network environment.
We are seeking an experienced network professional with strong hands-on experience supporting routers, switches, firewalls, VLANs, VPNs, ACLs, network segmentation, and high-availability network architectures. Candidates should be comfortable resolving complex Layer 2 and Layer 3 network issues, administering firewall platforms, and maintaining reliable, resilient network services.
Responsibilities
As a Lead Network Engineer, Firewall Infrastructure with AMERICAN SYSTEMS**,** you will:
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Lead network engineering, administration, and operational support activities in a highly classified environment.
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Design, implement, configure, and maintain enterprise network infrastructure, including:
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Routers, switches, and firewalls
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VLANs, ACLs, VPNs, and network segmentation
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High-availability, resilient network architectures
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Administer, monitor, troubleshoot, and maintain 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 issues involving routing, switching, firewall connectivity, access controls, and enterprise network services.
•
Support AAA, authentication, authorization, accounting, and network access control requirements.
•
Configure and troubleshoot 802.1X, VPN, and NAC solutions.
•
Support Cisco ISE environments, including authentication, authorization, policy enforcement, and network access control.
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Support network-related RMF, STIG, secure configuration, vulnerability remediation, and compliance activities.
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Develop and maintain network diagrams, implementation plans, standard operating procedures, configuration documentation, and technical reports.
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Partner with cybersecurity, systems administration, and mission teams to deliver reliable and resilient network services.
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Support network outages, root cause analysis, change implementation, remediation efforts, and incident-response activities related to network infrastructure.
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Monitor network performance and recommend improvements to availability, reliability, performance, and infrastructure resiliency.
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Provide technical leadership, mentoring, and guidance to network engineering and operations personnel.
Qualifications
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U.S. citizenship required.
•
Active Top Secret clearance required, with eligibility to obtain SCI and SAP access.
•
Bachelor’s degree in a related technical field, or additional relevant experience in lieu of a degree.
•
8+ years of experience in network engineering, network operations, network infrastructure, or firewall administration.
•
Active DoD 8140/8570 IAT Level II certification, e.g., Security+ CE, CySA+, SSCP, or an equivalent certification.
•
Active Cisco Certified Network Associate (CCNA) certification or higher-level Cisco networking certification.
•
Strong hands-on experience with enterprise network infrastructure, including:
•
Routing and switching
•
Layer 2 and Layer 3 troubleshooting
•
VLANs, subnetting, IP addressing, and network design
•
Access control lists (ACLs) and VPN technologies
•
Network segmentation and resilient network architectures
•
Hands-on experience administering and troubleshooting enterprise firewall platforms.
•
Experience with one or more of the following firewall technologies:
•
Cisco Firepower and Firepower Management Center (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, network access control, RMF, STIG, and secure configuration requirements.
•
Cisco ISE experience preferred, particularly with:
•
Authentication
•
Authorization
•
Accounting
•
Policy enforcement
•
Network access control
•
Experience troubleshooting Cisco routers, switches, firewalls, and enterprise network infrastructure.
•
Ability to work independently, lead technical efforts, and resolve complex network and firewall infrastructure issues.
•
Strong written and verbal communication skills.
Additional Experience We Value
The following experience is helpful but not required:
•
Experience supporting highly compartmented or special-access classified environments.
•
Advanced Cisco networking certifications, such as CCNP Enterprise, CCNP Security, or CCIE.
•
Experience with Palo Alto Networks, Fortinet, Check Point, or other enterprise firewall technologies.
•
Experience with Cisco ISE, NAC, 802.1X, or related access control platforms.
•
Experience supporting network modernization, infrastructure upgrades, technology refreshes, network migrations, or data center transformation efforts.
•
Experience developing network diagrams, implementation plans, configuration documentation, and standard operating procedures.
•
Experience with network change management, outage resolution, root cause analysis, and incident response in classified environments.
•
Familiarity with VMware or other virtualized environments.
Pay Transparency Statement
AMERICAN SYSTEMS is committed to pay transparency for our applicants and employee-owners. The salary range for this position is USD $155,000.00/Yr. - USD $180,000/Yr. Actual compensation will be determined based on several factors permitted by law. AMERICAN SYSTEMS provides for the welfare of its employees and their dependents through a comprehensive benefits program by offering healthcare benefits, paid leave, retirement plans, insurance programs, and education and training assistance.
EEO Statement
EEO Race/Sex/Disability Status/Veteran Status