Firewall Types and Implementation
A firewall is a network security system designed to prevent unauthorized access to networks. It monitors and controls incoming and outgoing network traffic as per the defined rules. A firewall can be implemented either in software or hardware form.
The prime objective of a firewall is to allow only authorized uses of the system and network and thereby restrict unauthorized access.
The CISA Review Manual covers the following types and implementations of firewalls:
Types of Firewall |
Types of Firewall Implementation |
Packet Filtering Router |
Dual-Homed Firewall |
Stateful Inspection |
Screened-Host Firewall |
Circuit Level |
Screened-Subnet Firewall |
Application-Level |