tunnel-doctor

An agent skill by daymade, from daymade/claude-code-skills. Tags: debugging, macos, networking, troubleshooting, vpn.

What it does

Diagnoses concrete tunnel and proxy-path failures across macOS and Windows/WSL: Tailscale routing, proxy env/system bypass, SSH double tunneling, VM/container propagation, stalled DNS, TUN DIRECT split-brain, Windows-host TUN cascades, and single-hop or chained proxy node/exit throughput. Use when Tailscale ping works but SSH/HTTP fails, browser returns 503 while curl works, Git SSH closes through the proxy, Docker pull/build fails behind TUN, getaddrinfo stalls while nslookup is fast, raw probes report physically impossible results, domestic DIRECT-routed sites fail while proxied sites work, a blocked port could be your tunnel or the destination's firewall, or the proxy is reachable but real downloads and full Git clones crawl. Also use when Git reports "failed to begin relaying via HTTP", ssh -vvv freezes at "debug2: resolving", ping works but dig times out, or setting up Tailscale SSH to WSL. Use debugging-network-issues only when the root cause remains unknown or belongs to an application/protocol layer.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add daymade/claude-code-skills --skill tunnel-doctor

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/daymade/claude-code-skills
cp -r claude-code-skills/tunnel-doctor ~/.claude/skills/tunnel-doctor

Safety box score

Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.

Source

Repository

daymade/claude-code-skills (all skills from this repository)

Path

tunnel-doctor/SKILL.md

Branch

main

Updated

2026-09-20

Related skills

• debugging-network-issues — Investigates network, streaming, and protocol failures with falsification-first layered experiments.
• macos-permissions — Diagnose and fix macOS TCC permission dialogs and silent denials — Screen Recording, Microphone, Camera, Accessibility, Automation (Apple Events).
• windows-remote-desktop-connection-doctor — Diagnose Windows App (Microsoft Remote Desktop / Azure Virtual Desktop / W365 / direct PC) connection issues on macOS.
• agents-debug — Use when your agent or environment is broken — wrong answers, errors, timeouts, tool failures, or CLI issues. Reads traces and logs to diagnose root causes.
• app-platform-troubleshooting — Debug running App Platform applications by accessing containers, analyzing logs, running diagnostics, and applying fixes.
• chrome-mcp-troubleshooting — Diagnose and fix Claude in Chrome MCP extension connectivity issues.