Our client, a specialist in advanced communication, navigation, and electronic warfare technologies, is seeking a Senior IT Network and Firewall Engineer to join their team in the Defence & Security sector. Based in Marlow, this role is integral to designing, deploying, and maintaining secure network environments supporting cutting-edge projects. Key Responsibilities: Build and deploy the required network infrastructure, ensuring readiness for ongoing support. Manage and troubleshoot secure development and reference environments. Design, administer, and maintain Corporate, Secure, and Development networks. Create and maintain firewall rule sets to safeguard network integrity. Handle IP switching and routing, subnetting, and VLAN configurations. Configure and maintain Palo Alto firewalls, Cisco & Aruba switches, and Aruba Wifi. Enterprise-grade encryption devices. Diagnose and resolve complex network issues effectively. Job Requirements: Proven experience with Cisco, Aruba, and Palo Alto. Experience with Intrusion Prevention/Detection and network monitoring (e.g., Darktrace). Strong understanding of network protocols, including IP switching, routing, subnetting, and VLANs. Hands-on experience with Cisco technologies and Cisco CMNA certification. Desirable Skills & Knowledge: Experience in Network Architecture. Knowledge of Software Defined Networking (SDN) technologies and ZTN (Zero Trust Networks). Posture checking and isolation. Port Authorisation Authentication (802.1x) Aruba/Fortinet. Palo Alto Networks - Firewalls (On-prem perimeter and Cloud-based appliances). Secure Proxy systems - Palo Alto Prisma (or others). MFA (RSA SecurID or similar hard/soft token systems). On-prem and Cloud security principles. Secure-by-design methodology. NIST 800-171 (CMMC CUI). Certifications: PCNSE - Palo Alto Certified Network Security Expert preferred (or working towards). Benefits: An opportunity to work on advanced technologies in the defence sector. A dynamic and innovative work environment. Competitive salary and benefits package. If you are an experienced network engineer looking for a challenging role within the defence sector, we would love to hear from you. Apply now to join our client's innovative team in Marlow. ADZN1_UKTJ