Linux Systems OR Network Engineer with GRE tunnels on Linux(Must)

Hello,

 

Greetings from Clifyx.

 

**********************************Visa independent************************

 

 

 

• Please Confirm Must Have Skills (TOP 3 SKILLS) –
• 6+ years Linux Systems or Network Engineering experience
• Experience working with GRE tunnels on Linux
• Strong packet capture and analysis skills using tcpdump, Wireshark/tshark
• Proficient with Bash and Python scripting
• Strong knowledge of iproute2, nftables/iptables, and tc
• Solid understanding of L2–L4 protocols, DSCP/QoS, and MTU mechanics

 

Role Overview
We are seeking an experienced Linux Network Engineer with strong scripting and packet‑analysis skills to support deep inspection of GRE tunnel traffic in a large‑scale, production network. The engineer will develop automation to extract, filter, and analyze encapsulated packets, and support operational troubleshooting for GRE‑related issues across the XWIFI Core Network.

This role requires expertise in Linux networking, GRE/ERSPAN, packet capture, filtering frameworks (nftables/iptables, tc), and scripting (Python/Bash). The contractor will collaborate closely with Comcast engineering teams while remaining an Infosys resource.
Key Responsibilities
• Develop Python/Bash scripts to inspect GRE tunnels and decapsulate/analyze encapsulated payloads
• Build automated capture flows using tcpdump, tshark, and libpcap
• Implement payload-aware filtering logic using nftables/iptables, tc (flower/clsact), and eBPF/XDP
• Troubleshoot GRE tunnel health, encapsulation/decapsulation errors, MTU/fragmentation issues, and offload behavior
• Create and maintain operational runbooks and documentation
• Integrate capture data and metrics with observability platforms (Prometheus, Grafana, ELK)
• Participate in on-call rotations as needed
Minimum Qualifications
• 6+ years Linux Systems or Network Engineering experience
• Experience working with GRE tunnels on Linux
• Strong packet capture and analysis skills using tcpdump, Wireshark/tshark
• Proficient with Bash and Python scripting
• Strong knowledge of iproute2, nftables/iptables, and tc
• Solid understanding of L2–L4 protocols, DSCP/QoS, and MTU mechanics
Preferred Qualifications
• ERSPAN (Type II/III) decoding experience
• GRE over IPv6 and GRE inside IPsec (xfrm)
• High‑rate packet capture frameworks such as PF_RING, DPDK, AF_PACKET
• Experience with eBPF-based tracing tools such as bpftrace and XDP loaders
• Experience writing CLI utilities in Python
• Prior experience supporting ISP/carrier environments
Success Metrics for the 1–2 Year Engagement
0–30 Days:
• Deliver GRE discovery and validation scripts
• Provide assessment of GRE visibility and tunnel health

30–90 Days:
• Implement automated selective payload capture workflows
• Produce updated dashboards and observability integrations

90–180 Days:
• Implement traffic filtering policies (nftables/tc) for GRE payload handling
• Build mature troubleshooting runbooks

6–24 Months:
• Harden capture and inspection pipelines for scale
• Lead GRE‑related diagnostics during incidents
• Support ongoing enhancements and network transformation initiatives
Contractor Expectations (Infosys-Specific)
• Must comply with Comcast engineering, documentation, and security standards
• Automation must include clear comments and handoff-ready documentation
• Daily work tracking via Jira and documentation in Confluence
• Collaborate effectively with Comcast and Infosys distributed teams