Senior Network Administrator (Secret Clearance #26-156)

Strategic Analysis, Inc.; Arlington (VA); On-site; USD 75,000 - 110,000; 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.

This role ensures high availability, security, compliance, and performance across enterprise systems by managing physical network gear and Microsoft 365 services in hybrid environments. The ideal candidate will troubleshoot complex issues, strengthen security, document solutions, and collaborate with IT teams to support end users and drive

Qualifications

• 3–7+ years of network or systems administration experience.
• Strong understanding of TCP/IP, DNS, DHCP, VLANs, routing, switching, and VPNs.
• Experience with enterprise-grade network hardware (Fortinet, Dell EMC, Sophos).
• Experience with Windows Server administration and Active Directory.

Responsibilities

• Administer and monitor on-premise network infrastructure including switches, routers, firewalls, wireless, and VPNs.
• Configure LAN/WAN, VLANs, routing protocols, and network segmentation.
• Manage Windows Server environments, AD, DNS, DHCP, and Group Policy.
• Support VMware ESXi and Hyper-V, including VM provisioning and performance optimization.
• Administer Microsoft 365 services and maintain hybrid configurations.
• Manage Azure AD/Entra ID identities, MFA, Conditional Access, SSO, and Azure AD Connect.
• Configure Intune/Endpoint Manager for device compliance and Autopilot deployments.
• Implement network and cloud security policies, including DLP and Zero Trust.
• Monitor performance using PRTG or SolarWinds; respond to alerts.
• Perform root-cause analysis and resolve issues across cloud and on-prem.
• Support disaster recovery planning, backups, and failover testing.
• Maintain accurate network diagrams, configuration records, and SOPs.

Skills

Troubleshooting

Documentation

Communication

Tools

PRTG

SolarWinds

VMware ESXi

Hyper-V

Fortinet/FORTIGATE

Azure AD/Entra ID

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.
• Microsoft 365 Administrator Expert or Azure Administrator Associate (AZ_104).
• Experience with backup and disaster recovery tools (Druva, Veeam, etc.).
• Knowledge of physical cabling standards and data center best practices.

Equal employment opportunity, including veterans and individuals with disabilities.