Senior Network Engineer LANType of contract: FreelanceLength: Long term, 1 year contract + extensionsLocation: Brussels, onsiteResponsibilitiesDesign, implement, and manage large-scale TCP/IP networks (>1,000 nodes) using CWDM, QoS, UTP, and fiber optic cabling.Administer CISCO and Nexus application switches across complex infrastructures.Manage Fortinet and CISCO firewall systems, SSL offloading devices, and encryption technologies.Support telecommunication protocols (VoIP, H.232) and ensure communication security.Monitor network performance using management, debugging, and load balancing tools (F5 ADCs).Oversee DHCP/DNS systems using Infoblox, Trinzic 825, and Network Services One/Grid.Perform structural cabling, fiber installations, and Ethernet switching/routing.Apply ITIL processes for change, incident, and configuration management.Lead network-level disaster recovery and ensure high availability across multiple sites.Support proxy servers, crypto devices, and secure dial-in systems with authentication/encryption.Manage network-related projects with a focus on security and scalability.Communicate fluently in English (C1 CEFR); French is highly desirable.Ensure compliance with network security protocols and maintain active security clearance.Profile RequirementsValid Security Clearance (mandatory).Degree in Computer Science (4 years) + 10 years of IT engineering experienceOr: 2 additional years of experience per missing academic year.CCNA Routing & Switching (minimum); CCNP or other advanced certifications preferred.Desirable: CCNA Data Centre, CCNA Cyber Ops, or similar.10 years: TCP/IP networks, CWDM, QoS, Ethernet switching, cabling, fiber installations, network monitoring.8 years: CISCO & Nexus switch administration.5 years: Fortinet/CISCO firewalls, SSL offloading, encryption, VoIP/H.232, ITIL, F5 ADCs, Infoblox, proxy servers.3 years (desirable): Project management, disaster recovery, multi-site network environments, crypto devices.1 year: Dial-in systems with secure authentication/encryption.Excellent English (C1); French is a strong asset.