Network Security Support Engineer

Network Security Support Engineer
Location: London (Hybrid - 2 days onsite per week)
Contract: 12-Month Fixed-Term Contract
Clearance: Active SC Clearance Required
Overview We are seeking an experienced Network Security Support Engineer to join a highly skilled security engineering team responsible for maintaining and supporting enterprise network security services. This role will focus on ensuring the availability, security, and operational stability of critical network security platforms, with particular emphasis on firewall and secure access technologies.
This is an excellent opportunity for a security professional with strong firewall administration and troubleshooting experience who enjoys working within complex enterprise environments.
Key Responsibilities

• Support and maintain enterprise network security platforms and firewall infrastructure.
• Manage and resolve incidents, service requests, and technical issues through to successful completion.
• Investigate and troubleshoot network and security-related problems using logs, monitoring tools, and traffic analysis techniques.
• Implement and validate firewall policy changes and security configurations in production environments.
• Perform root cause analysis for recurring incidents and recommend preventative improvements.
• Work closely with internal technical teams, third-party vendors, and managed service providers.
• Maintain technical documentation, operational procedures, and knowledge articles.
• Contribute to service improvements, platform optimisation, and operational best practices.
• Support platform maintenance activities, upgrades, patching, and vulnerability remediation.

Required Skills & Experience

• Strong hands-on experience supporting enterprise network security environments.
• Solid understanding of:
  • TCP/IP
  • DNS
  • DHCP
  • NAT
  • HTTP/HTTPS
  • TLS
  • VPN Technologies
• Experience with routing protocols including:
  • BGP
  • OSPF
• Practical administration and troubleshooting of Next-Generation Firewalls (NGFWs).
• Experience with firewall policies, NAT, VPNs, security profiles, and application controls.
• Ability to diagnose network and application connectivity issues using logs, monitoring tools, and packet captures.
• Experience working within ITIL-based Incident, Problem, Change, and Request Management processes.
• Strong communication and stakeholder management skills.

Preferred Experience

• Palo Alto Firewalls and Panorama.
• Fortinet Firewalls, FortiManager, and FortiAnalyzer.
• Secure Access Service Edge (SASE) solutions.
• F5 or similar application delivery technologies.

Desirable Skills

• Azure or AWS networking experience.
• Exposure to vulnerability management tools such as Tenable.
• Experience with email security platforms such as Mimecast.
• Basic scripting or automation skills using PowerShell, Python, APIs, or Infrastructure-as-Code tools.
• Relevant certifications such as:
  • Palo Alto
  • Fortinet
  • CCNA / CCNP
  • ITIL Foundation

What We're Looking For We're looking for a proactive and technically capable engineer who can work independently, take ownership of issues, and confidently support business-critical security infrastructure. The ideal candidate will have strong troubleshooting skills, attention to detail, and experience working within complex enterprise or regulated environments.
Active SC Clearance is essential for this role.