Performing Vlan Hopping Attack

---
name: performing-vlan-hopping-attack
description: Use when simulates VLAN hopping attacks using switch spoofing and double
  tagging techniques in authorized environments to test VLAN segmentation effectiveness
  and validate switch port security configurations against Layer 2 bypass attacks.
  . Use when working with performing vlan hopping attack.
domain: cybersecurity
tags:
- network-security
- vlan-hopping
- layer2-attack
- switch-security
- 802.1q
subdomain: network-security
version: '1.0'
author: oyi77
license: Apache-2.0
nist_csf:
- PR.IR-01
- DE.CM-01
- ID.AM-03
- PR.DS-02
category: cybersecurity
---

# Performing Vlan Hopping Attack

## Overview

Cybersecurity skill for performing vlan hopping attack. Follows industry best practices and security standards.

## When to Use
**Trigger phrases:**
- "performing vlan hopping attack"
- "Simulates VLAN hopping attacks using switch spoofing and double tagging techniqu"


- Testing the effectiveness of VLAN-based network segmentation during authorized penetration tests
- Validating that switch trunk port configurations prevent unauthorized VLAN access
- Assessing whether 802.1Q tagging and native VLAN configurations resist double-tagging attacks
- Demonstrating to network teams why proper switch hardening is critical for isolation between zones
- Verifying that DTP (Dynamic Trunking Protocol) is disabled on all access ports

**Do not use** on production switches without explicit authorization and change management approval, against critical infrastructure VLANs (SCADA, medical devices) without safety controls, or as a denial-of-service vector.


## When NOT to Use

- When you lack proper authorization for testing
- For production systems without change management
- When the task requires legal or compliance expertise beyond technical scope


## Prerequisites

- Written authorization specifying in-scope VLANs and switches for testing
- Physical or virtual access to a switch access port on the target network
- Yersinia, Scapy, and frogger VLAN hopping tools installed on Kali Linux
- Understanding of 802.1Q trunking, DTP, and VLAN tagging at the frame level
- Access to switch CLI for verification of configurations (read-only is sufficient)
- Wireshark for capturing and verifying tagged frames


> **Legal Notice:** This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

## Workflow

```python
# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. **Plan Operations** — Define objectives, scope, and success criteria for vlan hopping attack operations.
2. **Prepare Environment** — Set up tools, access, and data sources required for vlan hopping attack.
3. **Execute Core Workflow** — Perform the vlan hopping attack operations following established procedures.
4. **Validate Results** — Verify that results meet quality standards and objectives.
5. **Report Findings** — Document results, observations, and recommendations.
6. **Follow Up** — Track remediation actions and verify fixes where applicable.

## Tools

- **Analysis Platform** — Data processing and visualization
- **Collaboration Tools** — Team coordination and knowledge sharing


## Process

1. **Reconnaissance** — Gather target information, identify attack surface, enumerate services
1. **Analysis/Exploitation** — Execute the technique, analyze results, document findings
1. **Reporting** — Document IOCs, write findings, provide remediation recommendations

## Verification

- [ ] All vlan hopping attack procedures executed completely and documented
- [ ] Findings validated against multiple data sources
- [ ] False positives identified and filtered
- [ ] Results documented with evidence and timestamps
- [ ] Recommendations provided with risk-based prioritization

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |