Network Engineer III

Cornerstone Defense LLC; Belleville (IL); On-site; USD 100,000 - 120,000; Full time

Benefits offered by this job

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

Job summary

Cornerstone Defense LLC is seeking a Network Engineer III for Joint Fires Network (JFN) at Scott AFB, IL. The role leads senior-level troubleshooting, complex circuit redesign, and operational support in a 24x7 environment serving high-visibility DoD customers.

The candidate will handle configuration, optimization, and real-time routing changes, engage with customers, and document incidents end-to-end. DoD Top Secret clearance is required, with DoD-8570 IAT II certification prior to start.

Qualifications

• Bachelor’s degree with 4+ years relevant network experience.
• DoD-8570 IAT Level II certification (Security+ CE or equivalent) prior to start.
• Ability to work in a 24x7 shift environment.
• Deep understanding of IP and transport network topologies.

Responsibilities

• 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.

Skills

DoD IAT II

24x7 shift

IP/Transport topologies

Education

Bachelor’s degree

Tools

SolarWinds

Jira

Job description

Title

Network Engineer III - Joint Fires Network (JFN)

Location

Scott AFB, IL

Compensation Range

$100 - $120k

Clearance

Active DoD Top Secret required

Schedule

Rotating w/ 10% Travel

Company Overview

Cornerstone Defense is the Employer of Choice within the Intelligence, Defense, and Space communities of the U.S. Government. Realizing early on that our most prized assets are our employees, we continually focus our attention on improving the overall work/life experience they have supporting the mission. Our Team is pushed every day to use their industry leading knowledge to provide end-to-end solutions to combat our nation’s toughest and most secure problems. If you are looking for a place to not only be professionally challenged, but encouraged and supported by a company that cares, don’t look any further than Cornerstone Defense.

Benefits Overview

• 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

Position Description

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 24x7 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.

Qualifications

• 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 24x7 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.