A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predefined security rules. It is the primary control for preventing unauthorized external access to an organization ' s network, making it the best answer.
A. Firewall (Correct Answer) – Firewalls prevent unauthorized access by filtering traffic, blocking malicious connections, and securing the network perimeter.
B. Encryption – While encryption protects data confidentiality, it does not actively prevent unauthorized access to a network.
C. Antivirus – Antivirus software protects against malware and viruses but does not prevent unauthorized network access.
D. Biometrics – Biometrics controls physical or logical access (e.g., fingerprint authentication) but does not secure a network from external threats.
IIA GTAG 15 – Information Security Governance highlights firewalls as a critical security control for network protection.
IIA IPPF Standard 2110 – Governance emphasizes the need for network security policies that include firewalls.
NIST SP 800-41 Rev. 1 – Guidelines on Firewalls and Firewall Policy states that firewalls are the first line of defense in securing organizational networks.
Explanation of Each Option:IIA References:
