A cross-platform method for diagnosing network problems on Windows, macOS, and Linux, including DNS, VPN, and operating-system name-resolution issues.

Use it to investigate failed hostname lookups, applications that cannot connect, VPN DNS leaks, resolver configuration, and related system network faults.

It helps separate a general internet failure from a problem in the computer’s own DNS or network path, making troubleshooting more targeted.

net-ops — Skill for Claude Code by 0xDarkMatter/claude-mods

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add 0xDarkMatter/claude-mods --skill net-ops

Clone the repo

git clone --depth 1 https://github.com/0xDarkMatter/claude-mods

Made for: Claude Code.

Or install claude-mods, the plugin that ships this one along with the rest of its 112 skills, 3 commands, 3 agents, 4 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/net-ops/github.svg)](https://agentmods.dev/skills/0xdarkmatter/claude-mods/net-ops)

Your own site

<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/net-ops"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/net-ops/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/net-ops"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/net-ops.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 175 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 3,972 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector warn 7 Sept 2026

SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

high YARA Match · line 3
YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).

Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
medium Excessive Agency · line 157
Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.

Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00175	$0.03972
Opus 5.5	$0.00070	$0.01589
Sonnet 5.5	$0.00035	$0.00794
Haiku 4.5	$0.00017	$0.00397

Measured 1mo ago against content hash d496b132cadc, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

net-ops scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

The scan reads SKILL.md. This mod also ships 19 executable files (scripts/_lib/cache.sh, scripts/_lib/output.sh, scripts/_lib/redact.sh, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/net-ops/SKILL.md · 222 lines

How it starts

The opening of the file, as written. The whole thing — 222 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Network Operations

Diagnose network problems on Windows, macOS, or Linux with a layered ladder that isolates faults to the smallest possible scope, then pattern-match against OS-specific culprits. Designed for the common case: someone reports "internet broken" on a box you can shell into (locally or via SSH).

The Universal Insight

Bypass-tool succeeds while OS-resolver fails is a smoking gun on every platform. It means DNS infrastructure is healthy but the operating system's name-resolution path is hooked or misconfigured. The bypass tool differs per OS but the discriminator is identical:

OS	Bypass tool	OS resolver tool	If bypass works but resolver fails
Windows	`nslookup`	`Resolve-DnsName`, browsers	NRPT, WFP, HOSTS, LSP, local 127.0.0.1:53 proxy
macOS	`dig @1.1.1.1`	`dscacheutil -q host`, browsers	`/etc/resolver/*`, scutil DNS, profiles, mDNSResponder, kext
Linux	`dig @1.1.1.1`	`getent hosts`, `resolvectl query`	systemd-resolved, `/etc/resolv.conf`, NetworkManager, dnsmasq, NSS

The bypass tool implements its own resolver and talks straight to UDP/53. The OS resolver tool goes through the full system name-service path including all hooks. Comparing the two narrows the suspect list dramatically.

The Diagnostic Ladder

Walk down the layers in order. Do not skip rungs. Each rung has a binary outcome that eliminates everything above it. Per-OS tools are in references/diagnostic-ladder.md; the structure is universal.

1. Link layer        — interface up, valid IP, gateway present
2. IP reachability   — ping public IPs over ICMP
3. Socket reach.     — TCP/443 + UDP/53 to known destinations (raw socket DNS)
3.5 LAN services     — parallel track: mapped drives, SMB, mDNS/.local,
                       single-label hostnames (see below — internet OK ≠ LAN OK)
4. DNS infrastructure — bypass tool: nslookup / dig @<server>
5. OS resolver path  — the hook layer (most interesting on modern systems)
6. Application       — real HTTP request to a real hostname

Read the full file on GitHub · 222 lines

Files

What ships with it

24 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago Changed · +41 lines · +16 tokens per session d496b132cadc
1mo ago First seen · 181 lines · 159 tokens per session scan A dd767ef9c742

Subscribe to this mod's changes

net-ops is a skill published in the GitHub repository 0xDarkMatter/claude-mods (75 stars, last pushed 10d ago), licensed MIT. It adds 175 tokens to every session and 3,972 once invoked, about $0.0007 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Claude Code Debugging agent-skills ai-tools anthropic claude developer-tools

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