On which layer of the OSI model does the packet filtering firewalls work?

Packet filtering firewalls operate at the Network Layer of the OSI model. This layer is responsible for the transmission of data packets across network boundaries, which is a fundamental function of packet filtering firewalls. They analyze incoming and outgoing packets and make decisions based on set rules, such as IP addresses, protocols, and ports, to allow or block traffic. This is crucial for protecting the network from unauthorized access and potential threats.

References: The information aligns with standard networking principles and the functionalities of packet filtering firewalls as they are commonly understood in the field of network security123.