What type of firewall operates at Layer 2 to filter traffic between bridged interfaces without changing network addressing?

A transparent firewall operates at Layer 2 of the OSI model, which is the data link layer. This type of firewall filters traffic between bridged interfaces without altering the network addressing. It works by examining and controlling the traffic passing through it based on MAC addresses rather than IP addresses. Since a transparent firewall does not require changes to the existing network structure or additional IP addresses to manage traffic, it can be easily integrated into a network without disrupting ongoing services.

In contrast, host-based firewalls manage traffic on individual devices, making them more focused on protecting those specific systems rather than filtering traffic at the network layer. Stateless firewalls analyze packets independently without maintaining any context about ongoing connections, making them less effective for some types of traffic management compared to a transparent firewall. Hybrid firewalls combine features of both stateful and stateless firewalls to provide a more comprehensive security solution, but they do not specifically operate at Layer 2 like a transparent firewall does.