Senior Network Infrastructure Engineer in Caerphilly

25 days holiday entitlement rising to 28 days after 5 plus years’ service.

Holiday Purchase Scheme.

Company-supported CSR Volunteer Day.

2 days for personal wellbeing.

Pension – including Salary Sacrifice/Exchange for Pension scheme (SXP).

Electric Vehicle salary sacrifice scheme.

Death in Service – x4 basic salary.

Private Medical Insurance (partially subsidised).

SAGE Employee Benefits scheme.

Salary sacrifice charity donation scheme.

Ci Christmas Savings Club.

Ci Lottery.

Free parking at office.

Hybrid working arrangement – Mon & Fri optional WFH days.

Business Unit: Services.

Reporting to: Head of Service Architecture & Delivery.

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

Vetting requirements: Yes.

Company Overview: Centerprise International (Ci) was established in 1983 and has over 30 years of experience delivering innovative ICT products and services. Our financial strength, broad portfolio, and record of success in government contracts make Ci one of the UK’s leading ICT suppliers. We continually evolve to meet market demands, now offering Managed Services and Solution Design in addition to our own products. Ci actively attracts and develops talented individuals, providing the opportunity to build a varied career path within our group of companies. All employees learn from experienced professionals and see first‑hand how a thriving privately‑owned business operates.

Role Description: This role supports a major Defence customer delivering a secure, resilient, multi‑domain, on‑premise network architecture. The environment spans datacentre networks, secure LAN/WAN, SDN‑enabled virtualised domains, and deployed operational sites. You will be the senior engineer responsible for the design, operation and troubleshooting of the core network infrastructure, ensuring performance, reliability and adherence to MOD‑aligned security standards. We are seeking an experienced and highly skilled Senior Network Infrastructure Engineer to take a lead role in the design, implementation, and support of secure network solutions for a major Defence customer delivering a secure, resilient, multi‑domain, on‑premise network architecture. The position requires deep hands‑on experience across routing, switching, firewalls, segmentation, network security, and high‑assurance architectures. Exposure to software‑defined networking (e.g., VMware NSX) is highly advantageous. This senior position focuses on network architecture and operations in a secure Ministry of Defence environment, ensuring the network infrastructure is robust, compliant, and aligned with “Secure by Design” principles. The role will provide technical leadership within the network domain, serving as the top escalation point for complex issues and guiding best practices across the team.

Key Responsibilities:

• Lead the design, configuration and support of secure multi‑site LAN/WAN/SDN infrastructure across multiple security domains.
• Configure and optimise enterprise switches, including: (Cubic M3X S8G and M3X S24G – Cisco ESS3300 based).
• Implement and maintain routing protocols such as BGP, MPLS, VPLS, and supporting high availability patterns (HSRP/VRRP equivalents).
• Configure and maintain firewalls, VPNs, IDS/IPS and boundary protection systems.
• Support virtualised routing / network edge platforms including: (Cisco Catalyst 8000V (C8KV) with DNA Advantage & SD WAN components (T1/T2, on‑prem, HSEC)).
• Operate as the senior escalation point for complex networking incidents.
• Ensure compliance with MOD security standards and Secure by Design principles.
• Support MOD accreditation processes and security audits (e.g., IT Health Checks, CCVAs).
• Collaborate with cross‑functional teams (Security, Cloud, Virtualisation, Domain Services).
• Participate in Change Advisory Boards (CAB) and technical design reviews.
• Maintain network documentation, diagrams, and CMDB records.
• Drive innovation through evaluation of emerging networking technologies.
• Use or support network automation (Python, Ansible, PowerShell) where beneficial.
• Identify opportunities for simplification, resilience improvement and architectural uplift.

Experience and Skills:

• Extensive experience in multi‑site LAN/WAN environments.
• Advanced configuration (Cisco & Cubic).
• Deep knowledge of BGP, MPLS, VPLS.
• Deep understanding of routing protocols such as BGP, MPLS, VPLS, and segmentation in multi‑domain environments.
• VMware NSX and SDN.
• Network automation (Python, Ansible, PowerShell).
• Experience supporting high‑assurance or Defence/Government environments.
• High availability and redundancy (HSRP, VRRP).
• DNS, DHCP, NAT, IP planning.
• ITIL‑based service management.
• SD‑WAN & virtualised routing platform experience.
• VoIP and QoS.
• SIEM and log analysis (e.g., Splunk, Tanium).
• Experience in MOD or high‑security environments.
• Familiarity with JSP, ISO 27001, NIST.
• Experience leading technical projects.
• Existing SC/DV clearance.

Company Profile:

• Customer‑Centric: Committed to delivering exceptional service.
• Commitment: Dedicated to quality and reliability.
• Courage to Challenge: Willing to question and improve existing practices.
• Drive to Succeed: Results‑oriented and proactive.
• Dedication: Invested in team and organisational success.

Education/Qualifications/Specific training:

• Cisco CCNP R&S or Ent (required); CCIE (preferred by equivalent experience considered).
• ITIL v4 Foundation or higher.
• Degree in Computer Science, Network Engineering, or equivalent experience.