Agent skill · data analytics · daymade
debugging-network-issues
Investigates network, streaming and protocol failures with falsification-first layered experiments, the general fallback for unknown root causes. Use for ECONNRESET / RST_STREAM / SSE stalls, CDN/CGNAT timeouts or certificate errors, throughput collapse where everything returns 200 but transfers crawl, or LAN identity/topology mysteries. Not for known Tailscale/TUN/DNS/proxy-path conflicts (use tunnel-doctor).
Why this skill is useful
Provides a structured methodology for diagnosing complex network issues that the AI wouldn't reliably generate on its own.
What it needs
About 12k tokens when loaded. Last updated 2026-08-07. 1,320 stars on the source repository.
What this skill does
Debugging Network Issues Evidence-driven investigation methodology for incidents where the obvious cause is probably wrong. Built from a real 5-hour production case (see references/case-sse-rst-130s.md) where assumption-stacking wasted hours that a 10-minute layered experiment would have resolved. Apply this skill when the user reports a network/streaming/protocol symptom and the investigator feels tempted to diagnose from one log line or one circumstantial data point. The skill's job is to slow that reflex down. Triage first — is this a known domain? Before applying the general methodology below, check whether the symptom points at a stack that already has a dedicated skill in this repo. Those carry the domain-specific symptom→cause→fix tables this skill deliberately stays general about — start there, and come back here for methodology if the root cause turns out to be elsewhere. If the symptom is… Start with -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------- macOS Tailscale ⨯ proxy/VPN conflict (Shadowrocket / Clash / Surge): tailscale ping works but SSH/curl/git fails, Connection closed by 198.18.x.x, TUN DNS hijack, ~60s getaddrinfo resolver stall tunnel-doctor Cloudflare config: ERRTOOMANYREDIRECTS, SSL-mode mismatch, DNS / proxy-status issues behind the orange cloud cloudflare-troubleshooting Windows App / AVD / W365 RDP connection quality: WebSocket instead of UDP Shortpath, high RTT, STUN/TURN interference windows-remote-desktop-connection-doctor Client-side proxy / VPN / TUN misrouting: one specific site fails with ERRCONNECTIONCLOSED or SSLERRORSYSCALL, other sites work, DNS returns fake/TUN IPs, and adding a PROXY rule did not help this skill — read references/case-proxy-tun-cname-override.md first TLS certificate-verification errors (UNKNOWNCERTIFICATEVERIFICATIO …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills daymade/debugging-network-issues