Which statement best reflects the need to implement both preventive and reactive approaches for network security?

Which statement best reflects the need to implement both preventive and reactive approaches for network security?

• A. Preventive measures alone are sufficient.
• B. A combination of preventive and reactive approaches is necessary.
• C. Reactive measures alone are sufficient.
• D. Neither approach is necessary.

Answer: (B)

Security relies on a layered approach that combines prevention and detection/response because threats evolve and no single control is perfect. Preventive measures—such as firewalls, access controls, patch management, and system hardening—reduce the chance of an incident by blocking known risks. But even well-implemented preventions can fail due to zero-days, misconfigurations, or stolen credentials. That’s where reactive capabilities come in: detection to recognize that something has happened, containment to stop the spread, eradication to remove the threat, and recovery to restore normal operations. This combination minimizes both the likelihood of incidents and their impact, providing feedback to improve defenses over time. Relying on prevention alone leaves gaps, and relying on reaction alone means breaches can unfold before action is taken. Hence, a blend of both approaches is necessary for effective network security.

Security relies on a layered approach that combines prevention and detection/response because threats evolve and no single control is perfect. Preventive measures—such as firewalls, access controls, patch management, and system hardening—reduce the chance of an incident by blocking known risks. But even well-implemented preventions can fail due to zero-days, misconfigurations, or stolen credentials. That’s where reactive capabilities come in: detection to recognize that something has happened, containment to stop the spread, eradication to remove the threat, and recovery to restore normal operations. This combination minimizes both the likelihood of incidents and their impact, providing feedback to improve defenses over time. Relying on prevention alone leaves gaps, and relying on reaction alone means breaches can unfold before action is taken. Hence, a blend of both approaches is necessary for effective network security.