packet-tracer

packet-tracer is a skill for Claude Code, Codex from Mats2208/MCP-Packet-Tracer. It costs 139 tokens per session (7,577 once invoked), scanned A, original, MIT.

A guide and tool interface for controlling Cisco Packet Tracer, a program used to build and test computer networks. It covers planning network layouts, configuring devices, and checking the resulting topology.

In plain words
What is it for?
Use it to create routers and links, install modules, apply access rules and NAT, deploy changes to a running simulation, export configurations, and inspect the network.
Why use it?
It reduces errors when an agent works with Packet Tracer by requiring it to discover available devices, ports, modules, and commands before making changes.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create routers and links, install modules, apply access rules and NAT, deploy changes to a running simulation, export configurations, and inspect the network.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mats2208/mcp-packet-tracer/skill
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 Mats2208/MCP-Packet-Tracer --skill skill
Clone the repo
git clone --depth 1 https://github.com/Mats2208/MCP-Packet-Tracer

Made for: Claude Code, Codex.

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.

agentmods badge for packet-tracer

README.md
[![agentmods](https://agentmods.dev/badge/skills/mats2208/mcp-packet-tracer/skill/github.svg)](https://agentmods.dev/skills/mats2208/mcp-packet-tracer/skill)
Your own site
<a href="https://agentmods.dev/skills/mats2208/mcp-packet-tracer/skill"><img src="https://agentmods.dev/badge/skills/mats2208/mcp-packet-tracer/skill/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.

agentmods 80×15 button for packet-tracer

Your own site · 80×15
<a href="https://agentmods.dev/skills/mats2208/mcp-packet-tracer/skill"><img src="https://agentmods.dev/badge/skills/mats2208/mcp-packet-tracer/skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 139 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,577 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 medium

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 →

  • medium Memory Poisoning · line 88
    Skill attempts to fill the context window with filler content, displacing legitimate instructions and safety constraints. This can degrade agent performance or bypass safety boundaries.
    Fix: Implement context-window management that detects and rejects padding or stuffing attempts. Prioritize system instructions over user-injected content.
  • medium Excessive Agency · line 353
    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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00139 $0.07577
Opus 5 $0.00069 $0.03789
Sonnet 5 $0.00028 $0.01515
Haiku 4.5 $0.00014 $0.00758

Measured 10d ago against content hash 4354178e2230, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

packet-tracer 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 10d ago.

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.

skill/SKILL.md · 396 lines

How it starts

The opening of the file, as written. The whole thing — 396 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Packet Tracer MCP — operating guide

A Model Context Protocol server (packet-tracer) that drives Cisco Packet Tracer: plan a topology, validate it, generate IOS/PTBuilder artifacts, and live-deploy into a running PT over an HTTP bridge. The pt_* tools are your only interface — plus raw JS via pt_send_raw.

⛔ Prime directive: DISCOVER, never invent

The single biggest failure mode for a model driving this MCP is guessing — a model name, a port name, a slot id, a cable type, a module name, or a Script-Engine API method. Every one of these is discoverable, and a wrong guess either fails validation or (for raw JS) freezes Packet Tracer (see the modal-freeze rule below).

Rules:

  1. If you did not read it from a tool result, an MCP resource, or this skill, you do not know it — look it up first.
  2. Before planning/deploying: pt_list_devices, pt_list_templates, pt_get_device_details, and pt_list_modules (if installing modules).
  3. Before any raw JS: use only methods in the Verified Script-Engine API table below. If you need something not listed, probe it inside a try/catch before relying on it.
  4. After every mutation, read back with pt_query_topology / pt_export_topology and confirm.
  5. When something isn't in the catalog, say so — do not fabricate a device/module to fill the gap.

The bridge (mental model)

LLM ──▶ MCP server ──▶ HTTP bridge :54321 ──▶ MCP Control Center (PT extension) ──▶ PT Script Engine
  • The MCP queues JS at :54321; the PT extension polls /next every 500 ms and runs each command via $se('runCode', …) in PT's Script Engine, posting results back to /result.
  • XMLHttpRequest does NOT exist in the Script Engine (only in the extension webview). That's why all I/O goes through the bridge.
  • Confirm the link first with pt_bridge_status → must say "ACTIVE and CONNECTED". If "NOT connected", the user opens Extensions → MCP BUILDER in PT (or dismisses a stuck error modal).

Read the full file on GitHub · 396 lines

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.

  1. 10d ago First seen · 396 lines · 139 tokens per session scan A 4354178e2230

Subscribe to this mod's changes

packet-tracer is a skill published in the GitHub repository Mats2208/MCP-Packet-Tracer (173 stars, last pushed 10d ago), licensed MIT. It adds 139 tokens to every session and 7,577 once invoked, about $0.0007 per session on Opus 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.

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