Sr. Network Administrator

Job Details Location: 12291 Sunrise Valley Drive, Reston, VA, 20192, United States Job Category: OPS Employee Type: Exempt Required Degree: 4 Year Degree Travel: 75% Overview Sierra7, Inc. is seeking a Network Administrator to support the availability, security, and performance of a complex enterprise network serving a mission‑focused federal organization. This role is responsible for maintaining network connectivity across office, data center, and cloud‑connected environments; resolving advanced operational issues; improving monitoring and reliability; and supporting infrastructure modernization. The position works closely with other technology and security teams to reduce service interruptions, address vulnerabilities, and maintain consistent network standards. Work Schedule Monday through Friday, 8:00 a.m. to 5:00 p.m. Eastern Time, excluding federal holidays and Government closures. Occasional evening or weekend work may be required for emergencies, maintenance, incidents, or other mission‑critical needs. Position Responsibilities Administer and support enterprise LAN, WAN, wireless, VPN, and cloud‑connected network services. Configure, maintain, and troubleshoot routers, switches, firewalls, wireless access points, and related network appliances. Manage routing protocols, access controls, network segmentation, traffic prioritization, and secure remote connectivity. Monitor network health, capacity, availability, and security using enterprise monitoring and observability platforms. Investigate and resolve Tier II and Tier III network incidents, performance degradation, and service outages. Maintain network access control services, administrative authentication platforms, and endpoint posture controls. Support DNS, DHCP, IP address management, and certificate‑related network activities. Apply firmware updates, security patches, configuration standards, and vulnerability‑remediation actions to network devices. Create, test, maintain, and restore network‑device configurations. Perform daily operational checks and identify potential issues before they affect users or critical services. Support planned maintenance, infrastructure upgrades, deployment activities, and network‑improvement initiatives. Develop and maintain network diagrams, operating procedures, configuration records, troubleshooting guides, and other technical documentation. Participate in incident response, change control, problem management, and configuration‑management processes. Work with systems, cloud, cybersecurity, service desk, and application teams to resolve cross‑functional technical issues. Provide technical guidance to users, administrators, and other IT personnel. Support occasional evening or weekend maintenance, emergency response, or special operational activities when authorized. Perform work onsite at least three days per work week, with additional onsite attendance based on operational needs. Requirements Demonstrated experience administering multi‑site LAN and WAN infrastructure. Strong knowledge of enterprise routing and switching, including BGP and OSPF. Hands‑on experience with firewalls, VPNs, wireless networks, access‑control lists, segmentation, and quality‑of‑service controls. Experience administering network access control and secure device‑administration services. Working knowledge of DNS, DHCP, IP address management, and network‑related certificate processes. Experience using network monitoring, alerting, logging, and performance‑analysis tools. Ability to diagnose and resolve complex network incidents in production environments. Experience applying security patches, firmware upgrades, configuration baselines, and vulnerability‑remediation actions. Knowledge of configuration backup, recovery, standardization, and lifecycle‑management practices. Understanding of network security principles and their application within regulated or security‑sensitive environments. Experience following structured incident, change, and problem‑management processes. Strong technical documentation and written communication skills. Ability to communicate technical issues, risks, and recommendations to both technical and non‑technical stakeholders. Ability to work independently while collaborating effectively with infrastructure, cloud, and cybersecurity teams. Ability to work from the designated Reston, Virginia location a minimum of three days per week. Availability for occasional authorized work outside normal business hours. Education & Experience Bachelor's degree in Computer Science, or a related field. Five years of hands‑on experience supporting enterprise network environments. Preferred Qualifications Experience with Cisco, Palo Alto Networks, or Juniper technologies. Experience administering Cisco TACACS or comparable privileged network‑access platforms. Experience with Palo Alto firewalls and related security‑management tools. Experience supporting Microsoft Azure networking and cloud‑connected infrastructure. Experience supporting public‑sector, federal, public‑safety, or other mission‑critical environments. Familiarity with network automation using Python, PowerShell, Ansible, APIs, or configuration‑management platforms. Experience modernizing network monitoring, telemetry, or observability capabilities. Experience with behavioral analytics, cloud‑integrated monitoring, or automated performance remediation. Experience supporting geographically distributed offices, regional facilities, and data centers. Demonstrated success improving network availability, reducing incidents, strengthening security, or shortening recovery times. One or more relevant certifications, such as: Cisco CCNA or CCNP. CompTIA Network+. Palo Alto Networks PCNSE or CNSA. Microsoft Azure Fundamentals or a comparable cloud certification. Benefits FSA (Flexible Spending Account) HSA (Health Savings Account) Life Insurance, Voluntary Life Insurance, Voluntary Short‑ and Long‑Term Disability Additional Supplemental Medical Benefits Critical Care, Hospital Indemnity, Legal Plan, Accident 401K Legal Assistance Paid Time Off (PTO) Education Reimbursement Employee Referral Program Disclaimer The above statements are intended to describe the general nature and level of work being performed by people assigned to this classification. They are not to be construed as an exhaustive list of all responsibilities, duties, and skills required of personnel so classified. Sierra7 will not provide sponsorship for employment‑based immigration benefits for this position. To be considered for this position all candidates must reside in the United States and be a US Citizen. This position is not a C2C opportunity. Equal Opportunity Employer Sierra7 is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to any status protected by federal, state, or local law. Equal Opportunity Employer Veterans Disabled #J-18808-Ljbffr