Principal Network Security Consultant

Cleared Principal Network Security Consultant

Role Overview:

Our client is a leader in secure data centre and high-security network environments, serving technology and government sectors. They are known for delivering innovative, compliant, and resilient solutions in mission-critical settings.

Position Summary:

We are seeking a highly experienced Principal Network Security Consultant for an initial 6-month contract (with strong potential for extension) to lead the design and implementation of robust network security architectures in sensitive, high-security data centre and hybrid cloud environments. As a senior technical authority, you will provide expert guidance on security strategy, design, and delivery while mentoring teams and ensuring compliance with stringent regulatory standards.

Key Details:

• Employment Type: Contract
• Rate: Contact Me
• Duration: 6 months initial contract, with potential for extension
• Location: Hybrid/Client sites (regular onsite presence required for high-security environments)
• Clearance: Active DV (or eDV/MoD DV)

Key Responsibilities:

• Lead end-to-end technical design of advanced network security solutions, including secure data centre configurations and hybrid cloud architectures.
• Develop comprehensive High-Level Designs (HLD), Low-Level Designs (LLD), implementation plans, testing strategies, and handover documentation.
• Advise on and implement network segmentation, micro-segmentation, Firewall policy optimisation, and secure enclave strategies.
• Design secure routing, switching, and connectivity solutions to deliver high availability, resilience, and performance.
• Define and implement secure remote access, privileged access management, and Zero Trust models.
• Collaborate with stakeholders across security, infrastructure, and service delivery teams to ensure successful project outcomes.
• Support incident response and root cause analysis for network security events.
• Produce detailed technical documentation, including build guides, as-built records, and operational procedures.
• Mentor and guide junior engineers and delivery teams on best practices in secure network design and implementation.

Essential Skills & Experience:

• Significant senior/lead experience in network security consulting or architecture within regulated, government, or defence environments.
• Strong hands-on expertise in data centre network design, including routing/switching protocols (BGP, OSPF, VLANs, VRFs, QoS).
• Deep experience with enterprise Firewall platforms (Palo Alto, Fortinet, Check Point, Cisco ASA/FTD).
• Proven track record delivering secure network segmentation, controlled inter-zone connectivity, and secure ingress/egress traffic management.
• Solid understanding of NAC (eg, Cisco ISE), encryption, Zero Trust principles, and audit/compliance requirements.
• Experience designing and supporting resilient, high-availability network architectures.
• Active DV (Developed Vetting) clearance is required (or equivalent such as eDV/MoD DV).

Desirable Skills & Experience:

• Experience integrating with SIEM platforms (Splunk, Microsoft Sentinel, ArcSight).
• Exposure to load balancers/Application Delivery Controllers (eg, F5, A10) in secure environments.
• Knowledge of infrastructure-as-code tools (Ansible, Terraform) for network and security automation.
• Relevant certifications such as CCNP/CCIE (Security), PCNSE, CISSP, GIAC, NSE, or CCSE.

Call to Action:

If you hold active DV clearance and have the required expertise, please submit your CV for immediate consideration. This is an excellent contract opportunity to work on high-impact security projects in a challenging and rewarding environment.