Solution

The correct answer is To filter incoming and outgoing network traffic based on security rules.

Key Points

• The primary function of a firewall in network security is to filter incoming and outgoing network traffic based on security rules.
  • Firewalls establish a barrier between a trusted internal network and untrusted external networks, such as the Internet.
  • They inspect incoming and outgoing traffic and allow or block traffic based on predefined security rules.
  • Firewalls can help prevent unauthorized access, monitor network traffic, and protect against various types of cyber attacks.
  • They can be hardware-based, software-based, or a combination of both.
  • Firewalls are essential components in maintaining network security and ensuring data integrity.

Additional Information

• Firewalls can also provide additional features such as VPN support, intrusion detection and prevention, and content filtering.
• They help protect against common threats such as malware, phishing, and denial-of-service attacks.
• Modern firewalls may include advanced features like application-level filtering and user authentication.
• The concept of a firewall has evolved over time to adapt to new types of network threats and security requirements.