Devices Operating at Different Layers of the OSI Model

Malicious Attacks

Attacks like SQL injection or malware that firewalls can help prevent

Interfering

Preventing traffic between source and destination ports from affecting other devices

Layer 4 Firewall

Firewall that operates at the network and transport layers

Layer 7 Firewall

Firewall that operates at the session, presentation, and application layers, capable of decrypting and analyzing content

Software Firewall

Firewall that runs inside a virtual machine or physical server

Transport Layer

Layer at which firewall filter settings are port-based, allowing or blocking traffic from specific ports or protocols

Network Layer

Layer at which routers operate, connecting home network to the Internet

Firewall Layers

Multiple layers of the OSI model at which firewalls can operate, including data link, network, transport, session, and application

Router

Network layer device that connects networks or webserver to database server

Hardware Firewall

Physical device like Fortinet's Fortigate device that functions as a firewall

Standalone

A switch available as a single device

Integrated

A switch combined with other devices like wireless routers or modems

Business or Institutional Scenario

Context in which a router connects webserver to database server

Switch

Data link layer device that keeps traffic between source and destination ports separate

Filter Traffic

Defining what traffic should go between two networks based on IP addresses, ports, or content

Firewall

Device that operates at multiple layers of OSI model, filters traffic based on IP addresses, ports, and content

Cost of Firewall

Varies based on features, capabilities, and speed