COMPUTER NETWORKING

Detailed explanation-1: -Packet-filtering firewalls operate at the network layer (Layer 3) of the OSI model. Packet-filtering firewalls make processing decisions based on network addresses, ports, or protocols.

Detailed explanation-2: -Firewalls typically work on the network layer, the transport layer. However, some are also capable of working as high as the application layer, Layer 7.

Detailed explanation-3: -A packet filtering firewall is a network security technique that regulates data flow to and from a network. It is a security mechanism that allows packets to move across networks while controlling their flow through the use of a set of rules, protocols, IP addresses, and ports.

Detailed explanation-4: -Network firewalls are security devices used to stop or mitigate unauthorized access to private networks connected to the Internet, especially intranets. The only traffic allowed on the network is defined via firewall policies-any other traffic attempting to access the network is blocked.