Network Security Engineer

Network Security Engineer (Fortinet Firewall) | Contract | Greater South-East London You'll tighten up a multi-site retailer's Fortinet firewall estate. That means reviewing and rationalising existing policies, implementing segmentation, and securing traffic between stores and the data centre. It's hands-on implementation work, with FortiManager bringing consistency to how the estate is run. The essentials

• £400 to £450 per day, outside IR35
• 3-month contract
• 1 day a week on site What you'll actually do
• Review and rationalise existing FortiGate policies, removing rules that are no longer needed.
• Implement segmentation controls and restrict unnecessary east-west traffic.
• Secure store-to-data-centre communications across the WAN, including site-to-site VPNs.
• Support the rollout and adoption of FortiManager to improve firewall governance and consistency.
• Validate and test changes, using traffic analysis tools such as Wireshark to confirm they behave as intended.
• Work directly with the third-party network supplier and other providers to implement changes in an MSP-operated environment. What you'll need Essential
• Hands-on FortiGate deployment, administration and policy optimisation, plus FortiManager
• Implementing network segmentation with VLANs, ACLs and security policies
• Routing, switching and WAN, including site-to-site and remote-access VPNs
• Network troubleshooting and traffic analysis, including Wireshark
• Firewall change management and policy lifecycle work in MSP-operated environments
• A working understanding of Active Directory, Entra ID and MFA Nice to have
• FortiAnalyzer
• SD-WAN
• Azure networking
• Retail or other distributed, multi-site estate experience You'll also be comfortable acting on vulnerability management findings and giving network input to recoverability planning. You won't be running either programme. What's in it for you This is a clearly scoped piece of work with visible outcomes: a cleaner, more consistent firewall estate and segmentation you can point to. You'll work alongside a security architect on the same programme, so design and implementation stay connected.