Sigma Defense seeks Network Engineers (I, II, or III) to configure, install, and maintain DoD network equipment across Navy Enterprise architecture, including switching, routing, firewalls, wireless, and VoIP systems. Candidates will design and troubleshoot VLANs, routing protocols, IP addressing, and WAN connectivity while applying network STIGs and integrating external services. The role requires hands-on expertise with Cisco ISE, Palo Alto, next-gen firewalls, and deployment automation tools (Ansible, Python, PowerShell), scaling from 0–2 years (Level I) through 7+ years (Level III), with Security+ or CISSP certification mandatory.