Network Engineer
Location: Remote/London
Contract Duration: 3-6 months (very likely to extend)
Security Clearance: SC Cleared is essential
Working Pattern: Remote
We are seeking an experienced Senior Network Engineer with deep expertise in Squid Proxy, Palo Alto Networks Next-Generation Firewalls (NGFW), and Application Identification (App-ID) technologies to support, maintain, and enhance enterprise network security services.
The successful candidate will be responsible for the design, implementation, administration, and optimisation of secure web access platforms, Proxy services, and next-generation Firewall infrastructures. The role will focus on delivering secure, resilient, and compliant network services while supporting business-critical customer environments.
This position requires strong troubleshooting skills, security-focused thinking, and extensive experience with web Proxy technologies, application visibility, policy-based security controls, and enterprise networking.
Key Responsibilities
- Squid Proxy Administration
- Design, implement, configure, and support Squid Proxy environments.
- Manage forward, reverse, and transparent Proxy deployments.
- Configure and maintain ACLs, authentication services, and content filtering policies.
- Implement SSL inspection and certificate management solutions.
- Optimise Proxy performance, caching, and web traffic handling.
- Support Proxy migrations, upgrades, and platform refresh activities.
- Analyse Proxy logs and user traffic patterns to improve service performance and security.
- Palo Alto Firewall Administration
- Deploy, configure, and support Palo Alto Networks NGFW solutions.
- Design, implement, and maintain security policies aligned to business and customer requirements.
- Manage policy lifecycle including rule creation, optimisation, review, and cleanup.
- Configure and support:
- o App-ID
- o User-ID
- o Content-ID
- o URL Filtering
- o Threat Prevention
- o WildFire
- o GlobalProtect
- o SSL Decryption
- o Security Profiles
- Perform Firewall upgrades, patching, and hardware lifecycle management.
- Support high-availability deployments and failover testing.
- App-ID & Security Policy Management
- Utilise Palo Alto App-ID technology to identify, classify, and control application traffic.
- Create granular security policies based on applications, users, services, and business requirements.
- Analyse traffic flows and recommend security improvements using App-ID visibility.
- Replace Legacy port-based rules with application-aware security policies.
- Investigate and remediate application connectivity issues caused by policy enforcement.
- Develop rule-base optimisation strategies to reduce complexity and improve security posture.
- Network Operations & Troubleshooting
- Diagnose and resolve complex Layer 2-7 networking issues.
- Perform packet analysis using:
- o Wireshark
- o tcpdump
- o Firewall packet captures
- Troubleshoot:
- o Routing
- o DNS
- o NAT
- o SSL/TLS
- o Authentication
- o Application connectivity
- o Proxy access issues
- Support incident, problem, and change management processes.
Security & Compliance
Implement and maintain enterprise security controls.
Support vulnerability remediation programmes.
Participate in security audits and compliance assessments.
Ensure Proxy and Firewall services comply with internal and customer security standards.
Support Cyber Security teams during incident investigations and threat analysis.
Monitor security alerts and recommend remediation actions.
Required Technical Skills
- Proxy Services
- Squid Proxy Administration
- ACL Configuration
- SSL Bump/Inspection
- Kerberos Authentication
- NTLM Authentication
- LDAP Integration
- Proxy High Availability
- Web Filtering
- Palo Alto Technologies
- Palo Alto Firewalls
- Panorama
- App-ID
- User-ID
- Content-ID
- Threat Prevention
- WildFire
- GlobalProtect
- SSL Decryption
- URL Filtering
- Security Profiles
- Dynamic Address Groups
- Policy Optimisation
- Networking
- TCP/IP
- Routing Protocols (BGP, OSPF, EIGRP desirable)
- VLANs
- DNS
- DHCP
- NAT
- VPN Technologies
- Load Balancing
- High Availability Architectures
- Security
- Network Segmentation
- Zero Trust Principles
- IPS/IDS Technologies
- PKI
- TLS/SSL
- Secure Web Gateways
- Firewall Policy Management
- Monitoring & Toolsets
- Wireshark
- tcpdump
- Splunk
- SolarWinds
- ELK
- Grafana
- Palo Alto Panorama
- Network Monitoring Platforms
Essential Experience
5+ years supporting enterprise networking environments.
Proven operational experience with Palo Alto Networks firewalls.
Demonstrable experience implementing and managing App-ID security policies.
Strong experience supporting Squid Proxy environments.
Experience with security-focused network design and troubleshooting.
Experience working in highly secure or regulated environments.
Experience supporting production and customer-facing services.