IT- Systems Administrator

ISN; Bethesda (MD); On-site; USD 110,000 - 140,000; Full time

Benefits offered by this job

Comprehensive Medical Coverage

Flexible Spending Accounts (FSA)

Disability insurance (short & long)

Basic Life Insurance

401(k) Retirement Plan

Paid Time Off from day one

Professional growth and leadership dev

Job summary

ISN Corporation seeks a senior IT System Administrator to support and maintain our IT infrastructure. The role oversees Windows servers, Active Directory, DNS, DHCP, and core networking while delivering advanced technical support across the organization.

Ideal candidates have 8–10 years of system/network administration experience, strong Microsoft 365 and Azure AD skills, and hands-on VoIP and NAS/SAN experience. ISN offers a Drug-Free Workplace and equal opportunity employment.

Qualifications

• Experience administering Windows Server ecosystems and core services.
• Strong knowledge of AD, DNS/DHCP, and Group Policy.
• Experience managing Microsoft 365, Azure AD, Teams, and SharePoint.
• Good understanding of security practices, patch management, and incident handling.

Responsibilities

• Administer Windows servers, Active Directory, DNS, DHCP, and Group Policy.
• Support switches, firewalls, VPNs, and wireless networks.
• Configure and troubleshoot VoIP phones, call routing, and SIP/hosted voice systems.
• Maintain NAS/SAN storage appliances and shared drives.
• Manage Microsoft 365, Azure AD/Entra ID, Teams, and SharePoint.
• Provide Tier 3 support and handle escalations.
• Monitor backups, performance, patches, and updates.
• Maintain documentation, SOPs, and asset inventory.
• 8–10 years of experience in system/network administration.
• Strong expertise in Windows Server, Microsoft 365, and networking.
• Hands-on VoIP and network storage experience.
• Strong security practices and patch management.
• Ability to work independently and manage multiple priorities.

Skills

Windows Server administration

Network administration

Microsoft 365 administration

Security best practices

Documentation & SOPs

Tools

Active Directory

DNS

DHCP

Group Policy

Azure AD/Entra ID

SharePoint

PowerShell

Job description

Join a Company Where Your Work Makes a Difference

At ISN, we believe our people are the driving force behind our success. For more than 45 years, we've partnered with over 150 federal agencies to deliver innovative, mission-critical solutions that strengthen government mission and serve the public.

Recognized over 25 times by the Washington Business Journal as one of the 50 Fastest Growing Government Contractors and by the Inc. 5000 as one of the Fastest Growing Private Companies, ISN continues to grow through exceptional service, innovation, and a commitment to excellence. We have earned more than 100 commendation letters from our customers recognizing our commitment to exceptional quality, timely delivery, and unwavering integrity. We take pride in our role as a trusted government partner, delivering innovative solutions that benefit society, strengthen national security, and support mission-critical operations.

At ISN, you'll find more than a job—you'll find an opportunity to build your career, collaborate with talented professionals, and make a meaningful impact supporting important federal missions. We foster a collaborative, inclusive culture where employees are encouraged to learn, grow, share ideas, and contribute to innovative solutions for our customers.

Whether you're just beginning your career or bringing years of experience, you'll join a team that values integrity, accountability, teamwork, and continuous improvement. If you're passionate about making a difference and delivering exceptional results, we'd love to have you on our team.

Why You'll Love Working at ISN

• Comprehensive Medical Coverage with Prescription Benefits
• Flexible Spending Accounts (FSA)
• Company-Paid Short-Term & Long-Term Disability
• Company-Paid Basic Life Insurance
• 401(k) Retirement Plan
• Paid Time Off beginning on your first day of employment
• Professional growth and leadership development opportunities

We are seeking a senior-level IT System Administrator with 8–10 years of experience to support

and maintain our IT infrastructure. This role manages servers, networks, Microsoft 365, voice

systems, and network storage appliances while providing advanced technical support.

Key Responsibilities

• Administer Windows servers, Active Directory, DNS, DHCP, and Group Policy.
• Support switches, firewalls, VPNs, and wireless networks.
• Configure and troubleshoot VoIP phones, call routing, and SIP/hosted voice systems.
• Maintain NAS/SAN storage appliances and shared drive environments.
• Manage Microsoft 365, Azure AD/Entra ID, Teams, and SharePoint.
• Provide Tier 3 support and handle complex technical escalations.
Monitor backups, system performance, security patches, and updates.
• Maintain documentation, SOPs, and asset inventory.
• 8–10 years of experience in system/network administration.
• Strong expertise in Windows Server, Microsoft 365, and core networking.
• Hands-on experience with VoIP systems and network storage appliances.
• Strong understanding of security best practices and patch management.
• Ability to work independently and manage multiple priorities.

Preferred Qualifications

• VMware/Hyper-V experience
• PowerShell scripting
• Experience in compliance environments (NIST 800-171, CMMC)
• Certifications: Security+, Network+, Azure Administrator, CCNA, or similar

Position Summary

This role ensures stable IT operations, secure infrastructure, and advanced support across the

organization. Ideal for a seasoned administrator with broad hands-on experience.

ISN Corporation is proud to be an Equal Opportunity Employer.

We celebrate diversity and are committed to creating an inclusive workplace where all qualified applicants receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, disability, protected veteran status, genetic information, or any other status protected by applicable law.

ISN Corporation maintains a Drug-Free Workplace. All candidates must successfully complete a pre-employment background investigation prior to starting employment.