Location: Caerphilly (with travel to client / Ministry of Defence sites as required)

Clearance: SC (must hold or be eligible); DV highly desirable

Salary: 75,000 + Bonus + Comprehensive Benefits Package

About the Role

A 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 improvement.

Essential Experience

• Extensive multi‑site LAN/WAN experience.
• Advanced configuration skills on Cisco and Cubic platforms.
• Deep knowledge of BGP, MPLS, VPLS and segmentation.
• High‑availability technologies (HSRP/VRRP equivalents).
• DNS, DHCP, NAT, IP planning.
• Experience in secure or Defence‑oriented environments.
• ITIL‑based service management.

Desirable Experience

• VMware NSX and SDN, SD‑WAN and virtualised routing, VoIP, QoS, SIEM/log analysis tools.   Knowledge of JSP, ISO 27001, NIST. Experience leading technical projects.
• Existing SC/DV clearance.

Qualifications

• Cisco CCNP (required); CCIE desirable.
• ITIL v4 Foundation or above.
• Degree in Computer Science, Network Engineering or equivalent experience.

Personal Qualities

• Strong communicator.
• Analytical problem‑solver.
• Able to mentor and lead.
• Customer‑centric and proactive.

If you are a Senior Network Infrastructure Engineer with experience working in or with the Defence sector and looking for an exciting new challenge, please send your CV to me today.