Mid-Senior Network Engineer

Infinity Systems Engineering; Fort Belvoir (VA); On-site; USD 140,000 - 180,000; Full time

Benefits offered by this job

100% Company Paid Medical and Dental premiums

401(k) company contribution with free financial planning

Three weeks of vacation plus an annual company reward trip

48 hours of sick leave

Education and Professional Training Reimbursement

Profit Sharing Plan

Job summary

A technology consulting firm in Virginia is looking for a skilled Systems Administrator/Network Engineer. This role involves network design, implementation, and administration in a classified environment. Candidates should have a strong technical background and experience with both network and systems work. Thorough knowledge of cybersecurity best practices is essential, along with the ability to work both independently and as part of a team.

Qualifications

• 4+ years’ experience and a bachelor’s degree in Computer Science, Computer Engineering, or related.
• 5+ years of experience in network engineering, administration, or related IT roles.
• TS/SCI CI Poly clearance required.

Responsibilities

• Design and implement secure network infrastructure solutions.
• Monitor network performance, availability, and security.
• Implement and maintain network security measures.
• Provide Level 2/3 support for network-related issues.

Skills

Experience with network security, firewalls, and VPNs

Strong knowledge of networking protocols (TCP/IP, BGP, OSPF, VLANs)

Proficiency in configuring and managing routers, switches, and firewalls

Experience with network monitoring tools and troubleshooting methodologies

Understanding cybersecurity principles and network security best practices

Excellent problem-solving and communication skills

Strong experience in Juniper switch configuration

Proficient in Linux and Windows system administration

Active CompTIA Security+ CE or equivalent DoD 8570 baseline certification

Strong communication skills and a collaborative team mindset

Education

Bachelor’s degree in Computer Science or related field or 8 years of experience in lieu of degree

Job description

Job Summary

We are seeking a skilled Systems Administrator/Network Engineer to join our mission-driven team. This position offers a broad scope of responsibilities, including network infrastructure management (switch deployment & configuration) and system administration in a classified environment. The ideal candidate will be a self-starter with the ability to work independently while also contributing effectively in a collaborative, fast-paced team setting.

This role is ideal for someone with deep technical expertise, initiative, and experience supporting a mix of network and systems engineering and administration tasks.

Base pay range

$140,000.00/yr - $180,000.00/yr

Key Responsibilities

• Network Design & Implementation: Design and implement secure and scalable network infrastructure solutions. Configure and install network hardware, including routers, switches, firewalls, and wireless access points. Assist in developing network architecture to support business needs and growth. Configure, manage, secure, and troubleshoot Juniper and Cisco switches. Contribute to network and systems design in alignment with evolving mission requirements.
• Network Administration & Maintenance: Monitor network performance, availability, and security. Perform routine maintenance, updates, and patches for network devices. Identify and troubleshoot network issues, ensuring minimal downtime and optimal functionality. Configure, manage, secure, and troubleshoot Juniper and Cisco switches. Perform systems administration on Windows and Linux platforms (updates, security, troubleshooting, management). Maintain secure high performance KVM systems in an operational environment. Harden systems in accordance with DoD STIGs. Conduct and support ACAS scans and remediation. Assist with property accountability systems and technical logistics.
• Security & Compliance: Implement and maintain network security measures, including firewalls, VPNs, and access controls. Ensure compliance with industry standards, company policies, and regulatory requirements. Conduct network vulnerability assessments and respond to security threats. Support network VLANs, management & security, QoS, and routing protocols. Develop and maintain SOPs and technical documentation.
• Technical Support & Troubleshooting: Provide Level 2/3 support for network-related issues. Collaborate with IT teams to resolve connectivity problems affecting users and business applications. Document network configurations, troubleshooting steps, and resolutions. Support a wide range of IT and infrastructure-related duties based on mission need. Work with vendors and service providers to procure and maintain network equipment. Assist in evaluating new technologies and making recommendations for improvements. Coordinate with internal teams to support IT projects and initiatives.

Qualifications

Education: 4+ years’ experience and a bachelor’s degree in Computer Science, Computer Engineering, or related field, or a minimum of 8 years of experience in lieu of a degree. Candidates currently pursuing a degree may be considered if the timeline aligns with the position start.

Experience: 5+ years of experience in network engineering, administration, or related IT roles.

Clearance: TS/SCI CI Poly

Required Skills:

• Experience with network security, firewalls, and VPNs.
• Strong knowledge of networking protocols (TCP/IP, BGP, OSPF, VLANs, etc.).
• Proficiency in configuring and managing routers, switches, and firewalls.
• Experience with network monitoring tools and troubleshooting methodologies.
• Understanding cybersecurity principles and network security best practices.
• Excellent problem-solving and communication skills.
• Strong experience in Juniper switch configuration (Cisco experience is a plus)
• Proficient in Linux and Windows system administration
• Active CompTIA Security+ CE or equivalent DoD 8570 baseline certification
• Proven ability to work independently with minimal oversight
• Familiarity with network protocols, VLANs, and DoD IT environments
• Strong communication skills and a collaborative team mindset
• Commitment to security best practices and thorough documentation

Preferred Skills

• Industry certifications such as CCNA, CCNP, or equivalent.
• Experience with cloud networking (AWS, Azure, etc.).
• Familiarity with SD-WAN and network automation tools.
• Knowledge of VoIP and wireless networking solutions.

Work Environment

• Primarily office-based with occasional data center or network equipment room access.
• May require lifting and installing networking hardware (up to 50 lbs).
• On-call availability or after-hours support may be required for network incidents.

Work Schedule

This is a full-time position, typically working 40 hours per week. Overtime may be required depending on operational needs.

Infinity Benefits

• Great Company Culture. Infinity firmly believes that our success is due to the happiness and personal satisfaction of our employees.
• Health Benefits. 100% Company Paid monthly Medical and Dental premiums for you AND your family.
• Prepare for the Future. 401(k) company contribution, with free professional financial planning advisors
• Rest and Relaxation. Three weeks\' Vacation – and we offer an annual company reward trip after one year of employment.
• Health and Wellness. We offer 48 hours of sick leave, in addition to your Vacation, as well as Flex-Spending options (Medical and Dependent Care)
• Work that Stays at Work. Genuine work/life balance and flexibility. We know our employees have lives outside of work and we support you in living them!
• Education and Professional Training Reimbursement. We support our employees career aspirations and growth through our Education Reimbursement Program!
• Profit Sharing Plan. Infinity’s success is due to our employees which is why all eligible employees receive an annual payout based on our Profit-Sharing Plan.

U.S. Citizenship is required.

To learn more about our company and benefits, please visit: Infinity Careers

Anticipated Close Date: 11/10/25

Other job details

• Seniority level: Mid-Senior level
• Employment type: Full-time
• Job function: Information Technology
• Industries: IT Services and IT Consulting