A client in the Lorton, VA area is seeking a Sr. Systems Administrator to support a federal client. This position will provide system administration services to manage and maintain the equipment, networks and web applications that support the field communications systems deployed by our customer. The candidate will be subject matter expert skilled in Windows Server 2012 R2 and later, CentOS 7 and later, Active Directory, Active Directory Certificate Services (AD CS), Internet Information Services (IIS), OpenSSL, VMWare vSphere, VMWare vCenter Server, Windows 10, secure network architectures, hardware procurement/maintenance, system/network management tools, and backup solutions. Candidate MUST be able to earn a SECRET CLEARANCE Minimum Requirements-8+ years of relevant experience and BA - can substitute 6 years for Masters-Candidate must be independent - will work with customer on daily basis-Skilled maintaining Windows Server 2012 or 2016-Experienced maintaining CentOS 7 or later-proficient troubleshooting AD & AD Certificate Services issues-ability to troubleshoot VMware servers and build virtual servers-client has put emphasis that candidate will need to be skilled in VMware and building virtual servers - additionally candidates must be skilled and experienced in a centOS environment-Windows environment is moving from Windows Server 2012 to 2016/2019-ability to wait 3-4 weeks for agency suitability Desired Skills-BigFix Patch Management; deploy patches & fixlets from BigFix to endpoint servers & clients