vlan-hopping-attacks

vlan-hopping-attacks is a skill for Claude Code from akashrpatil/awesome-offensive-security-skills. It costs 67 tokens per session (875 once invoked), scanned A, original, Apache-2.0.

A guide to VLAN hopping, an attack that attempts to cross boundaries between isolated virtual networks on a misconfigured switch.

In plain words
What is it for?
Use it in authorized internal network assessments to test switch negotiation and double-tagging weaknesses, then validate the results.
Why use it?
It helps penetration testers verify whether network segmentation actually prevents traffic from reaching restricted VLANs.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is - [`_shared/references/elite-chaining-strategy.md`](../_shared/references/elite-chaining-strategy.md) — Exploit chaining methodology and high-payout chain patte.

Part of the cyberskills-elite plugin — 191 skills shipped together

Good fit Use it in authorized internal network assessments to test switch negotiation and double-tagging weaknesses, then validate the results.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/akashrpatil/awesome-offensive-security-skills
agentmods
npx agentmods add skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks

Made for: Claude Code.

Or install cyberskills-elite, the plugin that ships this one along with the rest of its 191 skills.

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 vlan-hopping-attacks

README.md
[![agentmods](https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks/github.svg)](https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks)
Your own site
<a href="https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks/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 vlan-hopping-attacks

Your own site · 80×15
<a href="https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/vlan-hopping-attacks.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 875 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.
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 $0.00067 $0.00875
Opus 5 $0.00034 $0.00438
Sonnet 5 $0.00013 $0.00175
Haiku 4.5 $0.00007 $0.00088

Measured 8d ago against content hash abb592a0b6b8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

vlan-hopping-attacks 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/process.py), 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/penetration-testing/network/vlan-hopping-attacks/SKILL.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

VLAN Hopping Attacks

When to Use

  • When conducting Internal Network Penetration Testing to comprehensively validate precisely if explicitly implemented VLAN segmentation restricts intrinsically network traffic To access sensitive segmented specifically networks (e.g., Workflow

Phase 1: Understanding VLAN Hopping (The Concepts)

# Concept: Virtual Local Area Networks (VLANs) isolate network traffic Attack ```

### Phase 2: Switch Spoofing (Dynamic Trunking Protocol)

```bash
# Concept: Cisco 1. Start specifically Yersinia GUI yersinia -G

# 2. Select ```

### Phase 3: Double Tagging (The 802.1Q Exploit)

```text
# Concept: If 1. Packet ```

### Phase 4: Validating the Hop

```bash
# Concept: Validate ```

#### Decision Point 🔀
```mermaid
flowchart TD
    A[Locate Target Switch Port ] --> B[Test DTP Negotiation ]
    B --> C{Switch accepts ```


## Prerequisites
- Network access to the target subnet (VPN, pivot, or direct connection)
- Nmap and relevant network scanning tools installed
- Understanding of TCP/IP, common protocols, and network segmentation
- Root/admin access on the attack machine for raw socket operations

## 🔵 Blue Team Detection & Defense
- **Explicit Access Ports**: The **VLAN Pruning and Security**: The Key Concepts
| Concept | Description |
|---------|-------------|
| DTP | Dynamic Trunking Protocol |
| 802.1Q | The |
## Output Format

Red Team Execution Protocol: VLAN Security Evasion

Target Infrastructure: Access Switch 04 Vulnerability: Dynamic Trunking Protocol (DTP) Enabled Severity: High (CVSS 7.2)

Description: During Action :

yersinia dtp -attack 1 -interface eth1

Impact : The ```

🛡️ Remediation & Mitigation Strategy

  • Input Validation: Sanitize and strictly type-check all inputs.
  • Least Privilege: Constrain component execution bounds.

📚 Shared Resources

For cross-cutting methodology applicable to all vulnerability classes, see:

Read the full file on GitHub · 101 lines

Files

What ships with it

2 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.

  1. 8d ago First seen · 101 lines · 67 tokens per session scan A abb592a0b6b8

Subscribe to this mod's changes

vlan-hopping-attacks is a skill published in the GitHub repository akashrpatil/awesome-offensive-security-skills (4 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 67 tokens to every session and 875 once invoked, about $0.0003 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 2026-09-03.

Related

Other skills, from other repositories

configuring-network-segmentation-with-vlans

Designs and implements VLAN-based network segmentation on managed switches to isolate network zones, enforce access control between segments, and reduce the attack surface by limiting lateral movement paths in enterprise network environments.

26zl/cybersec-toolkit · 48 tokens

configuring-network-segmentation-with-vlans

Designs and implements VLAN-based (802.1Q) network segmentation on managed switches to isolate zones such as corporate, servers, DMZ, guest, and IoT, and to limit lateral movement paths. Use when segmenting an enterprise network into isolated security zones, meeting compliance mandates (PCI-DSS, HIPAA, SOC 2) for…

Youngmaidainon/Agent-Level-Up · 93 tokens

analyzing-network-flow-data-with-netflow

Parse NetFlow v9 and IPFIX records to detect volumetric anomalies, port scanning, data exfiltration, and C2 beaconing patterns. Uses the Python netflow library to decode flow records, builds traffic baselines, and applies statistical analysis to identify flows with abnormal byte counts, connection durations, and…

mukul975/Anthropic-Cybersecurity-Skills · 76 tokens

meraki-network-ops

Cisco Meraki organization and network operations (read-only) — org discovery, network inventory, device inventory, clients, group policies, admins, licensing, alert settings via Cisco's official Meraki MCP. Use as the entry point for any Meraki question, to discover org and network IDs, or to inventory Meraki networks…

automateyournetwork/netclaw · 72 tokens

meraki-switch-ops

Cisco Meraki switching (read-only) — port configuration and status, VLANs, ACLs, QoS, STP, link aggregation, routing interfaces via Cisco's official Meraki MCP. Use when inspecting Meraki switch ports, auditing switch ACLs, or investigating port errors.

automateyournetwork/netclaw · 62 tokens

pwn-ai-mcp-combonation

Drive PWN::AI::MCP::ComboNation from pwneval.

0dayInc/pwn · 25 tokens