SC Cleared Senior Network Engineer - Squid Proxy Palo Alto Security

Network Engineer

Location: Remote/London

Contract Duration: 3-6 months (very likely to extend)

Security Clearance: SC Cleared is essential

Working Pattern: Remote

Inside IR35.

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.

________________________________________