configuring-network-segmentation-with-vlans

name	configuring-network-segmentation-with-vlans
description	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. . Use when working with configuring network segmentation with vlans.
domain	cybersecurity
tags	["network-security","vlan","network-segmentation","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"]

Configuring Network Segmentation With Vlans

Overview

Cybersecurity skill for configuring network segmentation with vlans. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "configuring network segmentation with vlans"

• "Designs and implements VLAN-based network segmentation on managed switches to is"

• Segmenting an enterprise network into isolated security zones (corporate, servers, DMZ, guest, IoT)

• Meeting compliance requirements (PCI-DSS, HIPAA, SOC 2) that mandate network isolation for sensitive data

• Reducing blast radius of security incidents by preventing lateral movement between network segments

• Isolating high-risk devices (IoT, BYOD, legacy systems) from critical infrastructure

• Implementing defense-in-depth by combining VLANs with firewall rules and access control lists

Do not use VLANs as the sole security control without Layer 3 filtering, for isolating networks that require air-gapping, or without proper switch hardening against VLAN hopping attacks.

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

• Managed switches supporting 802.1Q VLAN trunking (Cisco Catalyst, HP Aruba, Juniper EX, etc.)
• Layer 3 switch or firewall for inter-VLAN routing and access control
• Network design document specifying VLAN assignments, IP subnets, and traffic flow requirements
• Console or SSH access to switches with privileged configuration mode
• Understanding of 802.1Q trunking, STP, and inter-VLAN routing concepts

Workflow

# 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() -> :
     {k: re.findall(v, text)  k, v  IOC_PATTERNS.items()}