Ref: 1329007 Job Title: Senior Network Engineer DV Cleared Location: Cheltenham Salary: Up to £75,000 Lucronex have partnered with an expanding technology consultancy, who are dedicated to delivering high-impact solutions for the defence and public sector. As our client continue to scale, they are looking for a Senior Network Engineer to join their team in Cheltenham. They pride themselves on a collaborative culture and commitment to technical excellence, helping businesses navigate complex digital transformations with ease. Role Overview As a subject matter expert in networking, you will be designing, building and optimising complex network environments. Working on our clients enterprise network infrastructure, ensuring performance, scalability and reliability across a Juniper estate. Youll play a key role in driving continuous improvement, introducing automation and shaping the future of the clients network architecture. You will work across core, distribution and access layers, designing and maintaining a robust, high-performing, and secure network estate with a strong focus on Juniper technologies, SDN, automation and scalability across a spine a leaf environment. Key Responsibilities Design, implement and maintain a complex Juniper network across LAN/WAN, DC and edge architectures. Lead network projects particularly transformation, maintain best practices in design, performance and security. Own the design and deployment of SDN solutions using Juniper Apstra, ensuring consistency, automation and operational visibility across network fabrics. Integrate and support hypervisor-based virtual networks on ESXi, KVM and Proxmox platforms. Design and operate firewall and security policies, including zone-based firewalls, ACLs, NAT and edge security controls. Architect and manage IP routing environments, optimising performance and redundancy using BGP, OSPF and MPLS Deploy and maintain overlay and underlay networking technologies, including VXLAN, EVPN, and L2/L3 segmentation for multi-tenant environments. Maintain and enhance core network services, including Spanning Tree, ACLs, QoS, DNS and system monitoring. Drive network automation initiatives using Infrastructure as Code (e.g. Ansible, Python, Terraform). Collaborate closely with infrastructure, systems, and security teams to deliver resilient, scalable, and secure network solutions. Essential Requirements Strong expertise with Juniper networking hardware (MX, EX, QFX, SRX) and associated JunOS configuration and troubleshooting across multi-chassis solutions. Knowledge and hands-on experience with Juniper Apstra (SDN). Deep understanding of TCP/IP, routing, and switching, including BGP, OSPF, MPLS, VXLAN/EVPN. Working knowledge of firewall policies, VPN technologies, and load balancers. Understanding of datacentre interconnects (DCI) and multi-site architecture. Familiarity with virtualisation technologies such as ESXi, KVM and Proxmox. Practical knowledge of network automation tools and Infrastructure as Code methodologies. Practical experience with monitoring, alerting, and performance tools (SolarWinds, LibreNMS, Zabbix etc.) Strong grasp of network design principles and security best practices. Qualifications (Optional) JNCIA/JNCIP (or equivalent industry certifications or experience). Apply now for immediate consideration by sending your CV Please note, Lucronex is a specialist IT recruitment agency advertising this role on behalf of our client. As a recruitment agency, Lucronex operates in accordance with the Conduct of Employment Agencies and Employment Business Regulations 2003. We are committed to providing a professional and transparent service to all job seekers and employers. For further information about how we process your data and handle your application, please refer to our Privacy Policy available on our website