Senior Network Administrator

Strategic Analysis Incorporated; Arlington (VA); On-site; USD 90,000 - 140,000; Full time

Job summary

Strategic Analysis, Inc. is seeking an experienced Network Administrator to support, maintain, and enhance our on-premise and cloud IT infrastructure in a hybrid environment. The role emphasizes high availability, security, and seamless connectivity across our enterprise systems.

The ideal candidate will troubleshoot complex issues, manage Fortinet, VMware, and Microsoft 365 services, and collaborate with IT to strengthen security and perform regular documentation and DR testing.

Qualifications

• 3–7+ years in network or systems administration.
• Strong TCP/IP, DNS, DHCP, VLANs, routing, switching, VPNs.
• Hands-on with Fortinet, Dell EMC, Sophos hardware.
• Windows Server administration and AD.
• Microsoft 365 administration and hybrid identity.
• Familiar with Azure AD/Entra ID, CA, MFA.
• Experience with virtualization (VMware ESXi, Hyper-V).
• Familiar with PRTG or SolarWinds.
• Security best practices for network/cloud.
• Documentation and communication skills.
• Active government Secret or higher clearance or ability to obtain.

Responsibilities

• Administer and maintain on-premise network infrastructure including switches, routers, firewalls, wireless systems, and VPN solutions.
• Configure LAN/WAN, VLANs, routing protocols, and network segmentation.
• Manage Windows Server environments, including Active Directory, DNS, DHCP, and GPO.
• Support virtualization platforms such as VMware ESXi or Hyper-V, including VM provisioning and performance optimization.
• Administer Microsoft 365 services (Exchange Online, Teams, SharePoint, OneDrive) and maintain hybrid configurations.
• Manage Azure AD/Entra ID identity services, including MFA, Conditional Access, SSO, and Azure AD Connect.
• Configure Intune/Endpoint Manager for device compliance, configuration profiles, and Autopilot deployments.
• Implement and maintain network and cloud security policies, including firewall rules, DLP, Defender for Office 365, and Zero Trust principles.
• Monitor network and system performance using tools such as PRTG and SolarWinds; respond to alerts and outages.
• Perform root-cause analysis and resolve escalated technical issues across cloud and on-prem environments.
• Support disaster recovery planning, backups, and failover testing.
• Maintain accurate documentation including network diagrams, configuration records, and SOPs.
• Participate in infrastructure upgrades, cloud migrations, and modernization initiatives.
• Collaborate with IT team members to support end users and elevate issues when necessary.

Skills

Networking basics

Fortinet Fortigate

Windows Server

Azure AD

VMware ESXi

PRTG

SolarWinds

Security best-practices

Hybrid environments

Documentation

Active Directory

Tools

Fortinet Fortigate

Dell EMC switches

Sophos firewall

Hyper-V

Job description

Strategic Analysis is seeking an experienced Network Administrator to support, maintain, and enhance our on-premise and cloud based IT infrastructure. This role is responsible for ensuring high availability, security, compliance, and performance across all enterprise systems by managing the physical network systems (switches, firewalls, servers, etc.) as well as Microsoft 365 (Azure AD/Entra ID, Intune, etc.). The ideal candidate is a versatile, hands-on professional who can troubleshoot complex issues, strengthen security, and ensure seamless connectivity across hybrid environments.

Requirements:

• 3 -7+ years of experience in network or systems administration.
• Strong understanding of networking fundamentals: TCP/IP, DNS, DHCP, VLANs, routing, switching, and VPN technologies.
• Hands-on experience with enterprise-grade network hardware (Fortinet switches, Fortigate firewall, Dell EMC and Chassis, Sophos firewall, , etc.).
• Proficiency with Windows Server administration and Active Directory.
• Experience with Microsoft 365 administration and hybrid identity environments.
• Familiarity with Azure AD/Entra ID, Conditional Access, MFA, and Azure AD Connect.
• Experience with virtualization platforms (VMware ESXi,).
• Familiarity with network monitoring and packet analysis tools (PRTG, SolarWinds).
• Strong understanding of network and cloud security best practices.
• Ability to troubleshoot complex issues across hybrid environments.
• Strong documentation and communication skills.
• Active government Secret or higher-level clearance, or ability to obtain and maintain the clearance required

Responsibilities:

• Administer, monitor, and maintain on_premise network infrastructure including switches, routers, firewalls, wireless systems, and VPN solutions.
• Configure and manage LAN/WAN environments, VLANs, routing protocols, and network segmentation.
• Manage Windows Server environments, including Active Directory, DNS, DHCP, and Group Policy.
• Support virtualization platforms such as VMware ESXi or Hyper_V, including VM provisioning and performance optimization.
• Administer Microsoft 365 services (Exchange Online, Teams, SharePoint, OneDrive) and maintain hybrid configurations.
• Manage Azure AD/Entra ID identity services, including MFA, Conditional Access, SSO, and Azure AD Connect.
• Configure and maintain Intune/Endpoint Manager for device compliance, configuration profiles, and Autopilot deployments.
• Implement and maintain network and cloud security policies, including firewall rules, DLP, Defender for Office 365, and Zero Trust principles.
• Monitor network and system performance using tools such as, PRTG, or; respond to alerts and outages.
• Perform root_cause analysis and resolve escalated technical issues across both cloud and on_prem environments.
• Support disaster recovery planning, backups, and failover testing.
• Maintain accurate documentation including network diagrams, configuration records, and SOPs.
• Participate in infrastructure upgrades, cloud migrations, and modernization initiatives.
• Collaborate with IT team members to support end users and elevate issues when necessary.

Preferred Qualifications

• Fortinet NSE Certifications
• CompTIA Network+ or Security+.
• Experience with SAN/NAS storage systems.
• Experience with backup and disaster recovery tools (Druva, Veeam, etc.).
• Knowledge of physical cabling standards and data center best practices.

Strategic Analysis, Inc. is an Equal Opportunity employer and is committed to non-discrimination in employment. All qualified applicants will receive consideration for employment without regard to race, color, religions, sex (including pregnancy, sexual orientation, or gender identity), national origin, disability (physical or mental), age (40 or older), protected veteran status, genetic information (including family medical history) or any other characteristic protected by law. This policy includes but is not limited to the following employment actions: recruitment, hiring, firing, promotion, demotion, compensation, fringe benefits, training, mentoring and sponsorship programs.