network-engineer_skill

Overview

This skill acts as a hands-on network engineer for debugging connectivity, configuring load balancers, and analyzing traffic patterns. I handle DNS, SSL/TLS, CDN setup, and network security, and deliver actionable diagnostics, configs, and step-by-step remediation. Use this skill proactively for outage response, optimization, and protocol-level debugging.

How this skill works

I test connectivity across layers using tools like ping, traceroute, telnet, curl, tcpdump, and Wireshark, and validate DNS resolution from authoritative down to stub resolvers. For load balancers I generate practical nginx/HAProxy/ALB configurations and verify health checks and session behavior. I inspect SSL/TLS certificate chains, check cipher suites and OCSP/CRL status, and analyze traffic for latency, packet loss, and bottlenecks.

When to use it

• Intermittent or persistent connectivity failures between services or from clients
• When deploying or tuning load balancers and health checks
• Troubleshooting HTTPS failures, certificate errors, or TLS handshakes
• Diagnosing CDN cache behavior, origin pull issues, or cache misses
• Assessing firewall rules, security groups, or DDoS mitigation gaps

Best practices

• Test from multiple vantage points (client, edge, origin) before concluding root cause
• Document topology and packet flows; include diagrams for handoffs between components
• Start tests at lowest layer (ICMP/TCP) then move up (HTTP/TLS) to isolate issues
• Automate reproducible tcpdump/pcap captures and store with timestamps and context
• Keep minimal, reviewed firewall rules and use explicit health checks for load balancers

Example use cases

• Provide tcpdump and Wireshark capture commands plus analysis for a service experiencing packet loss
• Generate a production-ready nginx or HAProxy config that implements blue/green routing and sticky sessions
• Diagnose TLS handshake failures: validate certificate chain, SNI, supported ciphers, and OCSP responses
• Audit DNS resolution chain to find misconfigured delegation or TTL issues causing stale records
• Recommend CDN caching rules and origin shield settings to reduce origin load and improve latency