Definition:
A firewall is a security system, either in the form of software or hardware, designed to prevent unauthorized access to or from a private network. Its primary function is to enhance the security of devices connected to the network by acting as a “traffic barrier”. All network communications must pass through the firewall, where it decides whether to allow or block traffic, based on a set of predefined security rules.
How a Firewall Works
The main features and functions of a firewall include:
- Preventing unauthorized access: A firewall prevents unauthorized users from accessing a computer and its networks, thus protecting sensitive information and network resources.
- Communications monitoring: Monitors data traffic between internal and external devices over the Internet, ensuring that connections are secure and legitimate.
- Security alerts: Notifies about possible unauthorized or suspicious connection attempts from other computers, allowing network administrators to take preventive measures to protect systems.
This combination of functions makes firewalls an essential tool for maintaining the security and integrity of computer networks.
Types of firewalls
- Packet filtering firewalls: Analyze data packets attempting to enter or leave the network and filter them according to predefined rules.
- Stateful inspection firewalls: Monitor the state of active connections for more informed decisions about network traffic.
- Application firewalls: Operate at the application level, inspecting the contents of packets to detect specific threats.
- Next Generation Firewalls (NGFW): Combine traditional techniques with advanced functionalities for a more complete protection.
Importance of firewalls in cybersecurity
- Protection against external attacks: Helps prevent cyber attacks such as hacking, malware and ransomware.
- Access control: Allows the definition of specific access policies, ensuring that only authorized users and devices can interact with critical resources.
- Regulatory compliance: Firewalls are required by many security standards and regulations to protect sensitive data and comply with legal obligations.