What is the primary role of firewalls in perimeter security?

Firewalls play a critical role in perimeter security primarily by protecting against unauthorized access. They act as a barrier between a trusted internal network and untrusted external environments, such as the internet. By monitoring and controlling incoming and outgoing network traffic, firewalls enforce security policies that dictate what types of traffic are allowed and what types are blocked. This function helps prevent unauthorized users, attackers, and harmful traffic from penetrating the internal network, thus safeguarding sensitive data and systems from potential threats.

In the context of perimeter security, the focus is on establishing a secure boundary that deters or blocks potential intrusions. While aspects such as network speed, support for cloud services, and user experience are important considerations in overall network management, they do not define the primary function of firewalls. The core purpose remains centered on maintaining security by preventing unauthorized access, making option B the most accurate choice.