OSI Model

OSI Model

A conceptual framework that divides network communication into seven distinct layers to understand, troubleshoot, and secure network protocols.

Layer 7: Application Layer

Provides the interface for applications users work with, involving protocols such as HTTP, HTTPS, and FTP.

Layer 6: Presentation Layer

Handles data formatting, encryption, decryption, and compression to ensure the application can process data, using protocols like SSL and TLS.

Layer 5: Session Layer

Establishes, manages, and terminates sessions between applications, relying on protocols such as NFS and SMB.

Layer 4: Transport Layer

Provides reliable (TCP) or unreliable (UDP) end-to-end communication and error/flow control.

Layer 3: Network Layer

Handles logical addressing (IP) and routing of data packets across networks, using protocols like IP and ICMP.

Layer 2: Data Link Layer

Provides node-to-node data transfer and error detection, involving MAC addresses and protocols such as Ethernet.

Layer 1: Physical Layer

Transmits raw binary data (bits) over physical mediums, including cables and radio waves.

Session Hijacking

A security threat in the Session Layer where an active user session is taken over by stealing or predicting session tokens.

MAC Spoofing

A security threat in the Data Link Layer where a device impersonates another by changing its MAC address.

IP Spoofing

A security threat in the Network Layer involving the use of a false source IP address to hide identity or bypass filters.

DoS Attack

Denial-of-Service attack that floods a network with packets to disrupt service.

TLS/SSL

Protocols that ensure secure communication over a computer network, used for encrypting data.

Firewall

A security device or software that filters network traffic based on predetermined security rules.

Web Application Firewall (WAF)

A security layer designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet.

Defense-in-Depth

A multi-layered strategy for securing networks by implementing controls at multiple layers of the OSI model.