Networking - Network Segmentation

Network Segmentation is the process of dividing a large network into smaller, separate parts (segments) to improve security, performance, and manageability.

Simple Explanation

Imagine a big shopping mall. If there are no sections, people will crowd everywhere, making it hard to manage.
So the mall is divided into sections like clothing, electronics, food court, etc. This makes movement organized and easier to control.

Similarly, network segmentation breaks a network into smaller parts so data flows efficiently and securely.

Why Network Segmentation Is Important

✔ 1. Improves Security

If attackers enter one segment, they cannot easily reach other segments.
Example: Guests cannot access the internal office network.

✔ 2. Enhances Performance

Reduces unnecessary traffic by keeping local traffic within each segment.

✔ 3. Better Control

Makes it easier to monitor and manage network activity.

✔ 4. Limits Damage

If a virus attacks one segment, it won’t spread to the whole network.

How Network Segmentation Works

Networks can be segmented using:

1. VLANs (Virtual LANs)

Logically divide a network—like creating separate floors in a building, even on the same cable.

2. Subnets

Break a large IP network into smaller IP ranges.

3. Firewalls

Control what traffic is allowed between different segments.

4. ACLs (Access Control Lists)

Set rules that define which devices or apps can talk to each other.

Examples of Network Segmentation

A company may create different segments for:

  • Employees

  • Servers

  • Finance department

  • Guests/Visitors

  • IoT devices (CCTV, printers, sensors)

Each segment is isolated and protected with its own rules.

Real-Life Scenario

A corporate office has:

  • A guest WiFi network

  • An employee WiFi network

  • A secured server network

Guests can use the internet but cannot access company servers or employee devices.
This is network segmentation improving both security and performance.