(ISC)2 Certified in Cybersecurity Practice Exam

What devices enforce security policies by filtering incoming traffic?

1. Routers

2. Firewalls

3. Intrusion Detection Systems

4. Proxies

The correct answer is: Firewalls

Firewalls are specifically designed to enforce security policies by filtering incoming and outgoing traffic based on predetermined security rules. Their primary function is to establish a barrier between a trusted internal network and untrusted external networks, such as the internet. By analyzing packets of data, firewalls can determine whether to allow or block that traffic, thereby protecting systems from unauthorized access and potential attacks. They often provide features such as packet filtering, stateful inspection, and application-layer filtering, which allows organizations to mitigate risks and maintain a secure environment. Their ability to block certain types of traffic based on defined rules makes them an essential component of network security strategies. In contrast, while routers help direct traffic between networks and may include some basic security features, their primary role is not focused on filtering traffic at the level that firewalls do. Intrusion Detection Systems monitor network traffic for suspicious activity but do not filter or block the traffic themselves. Proxies act as intermediaries between clients and servers, which can also enhance privacy and security, but their primary role is not traffic filtering in the same sense as firewalls.