Which architecture for deploying a firewall is most commonly used in businesses today? why?

Answer: Screened Subnet Firewall

Explanation:

A screened subnet firewall is the most commonly used architecture for deploying a firewall today. Screened subnet firewalls are effective at blocking unauthorized access to network resources while maintaining traffic flow and communication between different parts of the business. Screened subnet firewalls can be deployed in a variety of ways, including as a standalone appliance, as part of an existing security infrastructure, or as a layer 2 solution integrated into an existing network infrastructure.

Screening tools can identify which traffic is and isn’t required for business operations, making it easier to block unauthorized access while still allowing essential traffic to pass. This allows screened subnet firewalls to protect network resources without slowing down business operations. Additionally, screened subnet firewalls can be augmented with intrusion detection and prevention (IDS/IPS) technologies to further protect against unauthorized activity.