This short-term contract role is focused on enhancing the security and functionality of RHEL 9 servers by enabling file uploads to Perplexity.ai while maintaining strict egress controls. The position requires a senior Linux and network security engineer to analyze outbound traffic, identify the necessary domains, IPs, and CIDRs for successful uploads, and develop a minimal, auditable, and secure outbound firewall ruleset. The engineer will also be responsible for implementing a command line prototype compatible with Perplexity.ai to validate the solution. The project is urgent and must be completed within 3–5 days, delivering a robust, well-documented solution suitable for enterprise environments.
Responsibilities
Analyze outbound network traffic on RHEL 9 servers during Perplexity.ai upload attempts
Identify all required domains, IP addresses, and CIDR ranges, including Cloudflare-backed endpoints
Develop and document a minimal, secure, and auditable iptables ruleset to enable uploads while maintaining a default DROP policy
Implement a command line prototype tool to validate file upload functionality to Perplexity.ai
Ensure the solution is robust, enterprise-ready, and accompanied by clear documentation for future audits and maintenance
Collaborate with stakeholders to ensure all security and operational requirements are met within the project timeline
Skills And Requirements
Extensive experience with RHEL 9, Linux networking, and iptables configuration
Deep understanding of egress firewall policies and best practices for secure server environments
Proven ability to analyze and troubleshoot network traffic, including the use of tools such as tcpdump and Wireshark
Familiarity with Cloudflare infrastructure and dynamic endpoint management
Strong scripting skills for developing command line prototypes (e.g., Bash, Python)
Ability to produce clear, comprehensive documentation for technical and non-technical audiences
Experience working in enterprise or high-security environments
Availability for immediate start and ability to deliver within a 3–5 day timeframe
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