SC Cleared Senior Network Security Engineer

Senior Network Security Engineer - Palo Alto/Squid Proxy

We are seeking an experienced Senior Network Security Engineer with strong expertise in Squid Proxy, Palo Alto Next-Generation Firewalls (NGFW) and application-aware security technologies.

You will join a major technology services consultancy supporting a secure enterprise customer environment, taking responsibility for the administration, optimisation and ongoing development of critical network security services.

This is a hands-on senior technical role requiring in-depth knowledge of secure web access, Proxy infrastructure, Firewall policy management and application-level traffic control.

Key Responsibilities:

• Design, configure, administer and support enterprise Squid Proxy environments.
• Manage forward, reverse and transparent Proxy services, including ACLs, authentication and web filtering.
• Configure SSL inspection, certificate management and Proxy authentication.
• Deploy, manage and optimise Palo Alto Next-Generation Firewalls.
• Develop and maintain Firewall security policies using Palo Alto App-ID, User-ID and Content-ID.
• Implement application-aware security controls, replacing Legacy port-based rules with granular application-based policies.
• Manage Palo Alto Panorama, URL filtering, Threat Prevention, WildFire and GlobalProtect.
• Perform Firewall upgrades, patching, policy reviews and lifecycle management.
• Support high-availability Firewall and Proxy architectures.
• Troubleshoot complex network, application connectivity, DNS, routing, NAT and SSL/TLS issues.
• Conduct packet analysis and root cause investigations using Wireshark, tcpdump and Firewall diagnostic tools.
• Support security audits, vulnerability remediation and incident management.
• Work closely with Cyber Security and infrastructure teams to maintain secure, resilient and compliant services.

Essential Technical Skills & Experience:

• Minimum 5 years' experience supporting enterprise network infrastructure.
• Strong hands-on administration of Palo Alto Networks Next-Generation Firewalls.
• Practical experience with Palo Alto App-ID and application-aware Firewall policy management.
• Experience managing Squid Proxy environments, including ACLs, authentication and SSL inspection.
• Good knowledge of Palo Alto Panorama and security features, including URL Filtering, Threat Prevention and User-ID.
• Strong understanding of TCP/IP, routing, switching, DNS, DHCP, NAT and VPN technologies.
• Experience with network security, segmentation, PKI and SSL/TLS.
• Strong Layer 2-7 troubleshooting and packet analysis skills.
• Experience supporting production services within secure or highly regulated environments.
• Familiarity with ITIL incident, problem and change management processes.

Desirable:

• Experience within Defence, Government or Critical National Infrastructure (CNI).
• Previous experience supporting secure customer accounts.
• Knowledge of secure web gateway technologies.
• Network security automation using Python or Ansible.
• Azure, AWS or hybrid cloud networking experience.
• Experience with Splunk, ELK or other security monitoring platforms.
• Palo Alto PCNSE, PCNSA, CCNA or CCNP certifications.