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Network Security - OSI Model

By IncludeHelp Last updated : July 23, 2024

What is OSI Model?

The Open System Interconnection (OSI) model is a fundamental framework that helps to understand and manage network communication. This model plays an important role in network security, providing a structured approach to securing network operations. In this article, we will go through the seven OSI model layers and emphasise their significance in network security.

Overview of OSI Model

This model makes us understand how applications communicate over networks. Its purpose is to guide developers in designing hardware and software and facilitate clear communication among network stakeholders.

The OSI model in Network Security consists of seven layers, each serving a specific purpose. These layers are:

1. Physical Layer: Protect Hardware

The physical layer of the OSI model ensures the physical components of the network are secure.

Example

Installing locks on server cabinets to prevent unauthorised access.

2. Data Link Layer: Secure Data Frames

The data link layer ensures data transmission between devices is secure.

Example

Using MAC address filtering on Wi-Fi routers to allow only trusted devices to connect.

3. Network Layer: Safeguard Routing

The network layer controls the routing of data packets across networks.

Example

Configuring firewall rules to block incoming traffic from suspicious IP addresses.

4. Transport Layer: Ensure Data Flow

The transport layer manages the reliable transmission of data between devices.

Example

Implementing HTTPS to encrypt data transmitted between a web browser and a server.

5. Session Layer: Manage Sessions

The session layer establishes, maintains, and terminates communication sessions.

Example

Generating session tokens for user authentication in online banking applications.

6. Presentation Layer: Encrypt Data

The presentation layer handles data encryption and decryption.

Example

Using SSL/TLS to encrypt email communication to protect sensitive information.

7. Application Layer: Secure Applications

The application layer protects applications from security threats.

Example

Regularly updating software to patch security vulnerabilities and prevent unauthorised access.

Why OSI Model is Important for Network Security?

The OSI model is important in network security as it helps us understand how data transfers through a network in different layers:

• The OSI model breaks down network communication into layers, which helps us understand how data transmission works.
• Each layer has vulnerabilities, so understanding them helps identify potential weak points in the network.
• Understanding which part of the network is most likely to be attacked helps us focus on protecting that part better.
• It provides a common framework for designing and implementing network protocols. This ensures compatibility between different systems and devices.
• It helps fix network problems by breaking down issues into smaller parts, so we know exactly where to look for the solution.

Read More: Transport, Network, and Application Layers Protocols