Network Engineer - Senior (Top Secret Clearance Required)

i3 Consulting; Chantilly (VA); On-site; USD 120,000 - 180,000; Full time

Job summary

i3 Consulting seeks a Senior Network Engineer to lead design, implementation, and optimization of secure, resilient networks for mission-critical operations. The role drives zero-trust modernization, cross-enclave interoperability, and end-to-end network governance.

Responsibilities include guiding architecture, ensuring secure communications, and coordinating with security, architecture, and operations teams in highly regulated environments.

Qualifications

• Extensive experience designing and supporting enterprise network environments.
• Expertise in routing, switching, firewalls, VPNs, and network security.
• Experience implementing zero-trust architectures and secure communications.
• Strong troubleshooting, performance analysis, and documentation skills.

Responsibilities

• Design and implement enterprise network architectures for secure, mission-critical ops.
• Lead zero-trust design initiatives and cross-enclave interoperability solutions.
• Optimize performance, reliability, and security across complex environments.
• Establish and enforce network security standards and governance.
• Drive modernization aligned with enterprise strategy and zero-trust principles.
• Ensure secure communications across classified and regulated environments.
• Provide technical leadership for network planning and implementation.
• Collaborate with security, architecture, and operations teams to maintain resilience.

Skills

Networking

Virtualization

Security

Network design

Leadership

Education

Bachelor's degree

Master's degree (preferred)

Tools

Cisco

Arista

VPNs & Tunneling

VMware

Proxmox

Nutanix

Nessus

Splunk

Nginx

Jira

Confluence

Docker

Kubernetes

Job description

Network Engineer - Senior

"Bachelors required Minimum 8 years experience This role leads the design, implementation, and optimization of resilient, secure network infrastructures supporting mission-critical operations. The SME provides strategic and technical leadership in network modernization, security architecture, and performance optimization while ensuring secure and reliable communications across complex, multi-enclave environments."

Unique Skills / Technical Requirements

• Networking
  • o Cisco: Switching, Routing, Firewalling, and Site-to-site functionality (such as IPSEC, DMVPN, and SD-WAN)
  • o Arista: Switching
  • o Tunneling & VPNs: GRE, IPSEC, SSH, SSL, OpenVPN, Wireguard, and specialized multi-tiered applications
  • o Virtual Distributed Switching: VMWare, Proxmox, and Nutanix
  • o Solutions & Hardware: Client-Server VPNs, Site-to-site VPNs, and ad-hoc vendors or equipment
• Virtualization / Hyper-Converged Infrastructure
  • o VMWare / Broadcom: ESXi (vSphere), vCenter, VSAN, VxRail, Cluster management, and Licensing
  • o Proxmox: Host and cluster configuration/management, Networking, and Ceph configuration/management
  • o Nutanix: Host and cluster configuration, management with Prism Central, and NDFS configuration/management
• Large Data Storage Technologies
  • o Hardware/Vendors: QNAP, Synology, TrueNAS, and NetApp
  • o File Transport Protocols: Samba, SSH, SFTP, and NFS
• Monitoring & Security
  • o Monitoring: Network-based and Host-based collection and monitoring
  • o Alerting & Scanning: Internal and external alerting (including SMTP configuration), and Active vulnerability scanning (such as Nessus)
  • o SIEM: Splunk familiarity
• System Administration
  • o Operating Systems: Linux (e.g., Rocky, RedHat, Amazon, Ubuntu), Windows, and Mac OS
  • o Identity & Access Management: IPA / FreeIPA, LDAP / OpenLDAP, Keycloak, and Linux-based SSSD host-based access control (HBAC)
• Applications
  • o Splunk, Nginx, Confluence, Jira, Docker, Kubernetes, GitLab, and Jupyter

Key Responsibilities

• Design and implement enterprise network architectures that support secure, mission-critical operations.
• Lead zero-trust network design initiatives and cross-enclave interoperability solutions.
• Optimize network performance, reliability, and security across complex, multi-enclave environments.
• Establish and enforce network security architecture standards and governance processes.
• Drive network modernization efforts aligned with enterprise strategy and zero-trust principles.
• Ensure secure communications and connectivity across classified and highly regulated environments.
• Provide technical leadership for network infrastructure planning and implementation.
• Partner with security, architecture, and operations teams to maintain resilient network systems.

Required skills:

Extensive experience designing and supporting enterprise network environments. Strong expertise in routing, switching, firewalls, VPNs, network security, and access control technologies. Experience implementing zero-trust architectures and secure communications solutions. Advanced troubleshooting and network performance analysis skills. Experience supporting mission-critical, highly secure, or regulated environments. Strong leadership, communication, and technical documentation skills.

Preferred skills:

Master's degree in Information Technology, Network Engineering, Cybersecurity, or related field. Experience supporting federal, defense, intelligence, or classified network environments. Expertise with multi-enclave or cross-domain network architectures. Experience with cloud networking, software-defined networking (SDN), and hybrid cloud environments. Knowledge of security accreditation processes and compliance frameworks. Relevant certifications such as CCNP, CCIE, CISSP, JNCIP, JNCIE, AWS Advanced Networking, or equivalent.