Senior Network Engineer (Squid Proxy & Palo Alto Security)
CBSbutler Holdings Limited trading as CBSbutler Senior Network Engineer (Squid Proxy & Palo Alto Security)
Summary
Contract role (up to £780/day inside IR35) for a senior network engineer to own and optimise enterprise Squid proxy and Palo Alto next-gen firewall services — security policies, SSL decryption, packet analysis and upgrades — hybrid with two onsite days per week. Requires active SC clearance and sole UK national status.
Salary: £? - ? per year
Requirements:- 5+ years experience supporting enterprise network infrastructure.
- Strong hands-on administration and support experience with Palo Alto Networks firewalls.
- Demonstrable experience configuring and managing Palo Alto App-ID security policies.
- Extensive experience with Squid Proxy, including ACLs, SSL inspection and authentication.
- Experience with Palo Alto Panorama, User-ID, URL Filtering and Threat Prevention.
- Strong understanding of TCP/IP, routing, VLANs, DNS, DHCP, NAT and VPN technologies.
- Experience troubleshooting SSL/TLS, authentication and application connectivity issues.
- Proficiency with network analysis tools such as Wireshark and tcpdump.
- Experience working within highly secure, regulated or business-critical environments.
- Active SC clearance and sole UK national status.
- Desirable: experience in Defence, Government or Critical National Infrastructure, or supporting secure customer environments.
- Desirable: knowledge of network segmentation and Zero Trust security principles.
- Desirable: experience with infrastructure automation using Python or Ansible.
- Desirable: familiarity with monitoring platforms such as Splunk, SolarWinds, ELK or Grafana.
- Design, implement, configure and support enterprise Squid Proxy environments, including forward, reverse and transparent proxy deployments.
- Administer and optimise Palo Alto Next-Generation Firewalls, including Panorama management.
- Develop and maintain granular firewall security policies using Palo Alto App-ID, User-ID and Content-ID technologies.
- Configure and manage URL filtering, Threat Prevention, WildFire, GlobalProtect and SSL decryption.
- Manage proxy ACLs, authentication integrations, SSL inspection and web filtering policies.
- Review and optimise firewall rule bases, transitioning legacy port-based rules towards application-aware security policies.
- Troubleshoot complex network and application connectivity issues across Layers 2–7.
- Perform packet analysis using tools such as Wireshark and tcpdump.
- Support firewall and proxy upgrades, migrations, patching and high-availability configurations.
- Work alongside Cyber Security teams to support vulnerability remediation, incident investigations and security compliance activities.
- Ansible
- Architect
- ELK
- Firewall
- Grafana
- Support
- NAT
- Network
- Python
- Security
- Splunk
- TCP/IP
- VPN
- Web
More:
We are seeking an experienced Network Architect or Senior Network Engineer to support and enhance secure enterprise network infrastructure, taking ownership of critical proxy and firewall services and focusing on secure web access, application visibility, security policy management and network optimisation. The role is based in Kent, with two days per week onsite, and pays up to £780 per day inside IR35.
last updated 45 week of 2026