Administers and troubleshoots enterprise Cisco networking, routing, switching, firewalls, servers, virtualization, cloud infrastructure, and security systems. Performs maintenance, upgrades, vulnerability remediation, monitoring, documentation, and recovery activities. Provides advanced technical support, user guidance, and help desk escalation assistance. Leads infrastructure projects, manages assigned work groups, maintains network diagrams and technical procedures, and supports Microsoft Azure, AWS, VMware, FortiGate, and related enterprise technologies.