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# Network Engineer III

- **Company:** Cornerstone Defense
- **Location:** Belleville, IL, United States
- **Experience:** Experienced
- **Salary:** $100,000.0 - $120,000.0
- **Contract:** Permanent contract
- **Skills:** Microsoft Access, Microsoft Word, Microsoft Excel, JIRA, Synchronous Optical Networking, Microsoft Outlook, Cyber Security, Multi-protocol Systems, Local Area Networks, Network Troubleshooting, Network Control, Microsoft PowerPoint, Network Routers, Computer Network Operations, Juniper, SolarWinds (Software), Cisco
- **Published:** September 1, 2026
- **Apply:** https://www.dice.com/job-detail/8c26c4af-d288-454c-bef3-57cf5d53eb82

## About the Role

* Bachelor's degree and 4+ years relevant experience, or equivalent combination of education/experience.
 * DoD-8570 IAT Level II certification (Security+ CE or equivalent) prior to start date.
 * Ability to work in a 247 shift environment.
 * Deep Understanding of IP and Transport network topologies.

Preferred:

 * Experience within tech control or cyber transport environments.
 * Background in circuit actions and vendor coordination.
 * Strong IP/Transport architecture experience.
 * Experience with SolarWinds and Jira.
 * Telco NOC, inside plant, or outside plant experience.
 * Proficiency with MS Office Suite (Outlook, Excel, Word, PowerPoint, Access, Teams).
 * Experience in one or more: alarm surveillance, fault management, LAN maintenance, performance management, change management.

## Description

Cornerstone Defense offers a very comprehensive benefits package including, but not limited to: Medical, Dental and Vision Plans * Generous PTO Policy * 401(k) * HSA and FSA options * Life and Disability Insurance * Tuition Reimbursement and Training * Perks at Work Discount Program * Referral Program * Leads Generation Program * CollegeAmerica 529 * Fitness Reimbursement Program * Travel Assistance * Norton Lifelock Benefit Solutions * Life Planning Financial & Legal Services *, The Network Engineer III serves as a senior-level network operations engineer responsible for advanced network troubleshooting, complex circuit redesign, deep analysis of transport/IP connectivity, and leadership-level operational support within a 247 environment. This role requires substantial technical proficiency, strong situational judgment, and the ability to independently resolve multi-layer transport and IP issues impacting high-visibility DoD customers.

Core Tasks:

 * Execute network operations involving configuration, analysis, and optimization of customer circuits across optical multiplexers, electro-optical systems, routers, and switches.
 * Perform real-time circuit redesign and routing adjustments to restore connectivity during outages, maintenance events, or unexpected network degradations.
 * Engage directly with internal customers, external agencies, service providers, and higher-tier engineering teams to maintain maximum network availability.
 * Proactively monitor alarms using platform-specific network management tools to rapidly detect service-impacting conditions.
 * Perform change-management tasks including hardware replacements, platform configurations, and ASI updates.
 * Use incident management applications to thoroughly document outages, escalation paths, troubleshooting actions, root cause isolation, and resolutions.
 * Assess, diagnose, and recommend corrective actions for advanced network issues using deep expertise across routers, switches, crypto devices, Cisco, Juniper, MSPP, optical transport, MPLS, TDM, and SDH/SONET networks.