Senior Network Infrastructure Engineer - Defence Programme Location: Caerphilly (with travel to client / Ministry of Defence sites as required)Clearance: SC (must hold or be eligible); DV highly desirableSalary: 75,000 + Bonus + Comprehensive Benefits PackageAbout the RoleA major Defence programme is seeking a highly skilled Senior Network Infrastructure Engineer to lead the design, implementation and ongoing support of secure, resilient, multi?domain network services. You will work across datacentre networks, secure LAN/WAN, SDN?enabled virtualised environments, and deployed operational sites - ensuring high availability, compliance and adaptability in a mission?critical environment.Key Responsibilities Lead the design, configuration and support of secure multi?site LAN/WAN/SDN infrastructure. Configure and optimise enterprise switching platforms (e.g., Cubic M3X S8G / S24G, Cisco ESS3300?based). Implement routing protocols including BGP, MPLS, VPLS, and HA technologies. Configure firewalls, VPNs, IDS/IPS and boundary protection systems. Support virtualised routing and SD?WAN technologies (Cisco Catalyst 8000V). Act as senior escalation point for complex incidents. Ensure compliance with MOD security standards and Secure by Design principles. Maintain documentation, diagrams and CMDB records. Support accreditation processes (IT Health Checks, CCVAs). Contribute to network automation (Python, Ansible, PowerShell). Identify opportunities for architectural ..... full job details .....