FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -(A circuit proxy filter firewall operates at the session layer. It verifies the sequencing of session packets, breaks the connections, and acts as a proxy between the server and the client. An application layer firewall operates at the application layer, examines the entire message, and can act as a proxy to clients.

Detailed explanation-2: -They both serve as an intermediary between servers and clients. Each can cache web pages to reduce network congestion and both conceal information about the user from the server. A proxy firewall does a deeper level inspection of network traffic to identify and protect against potentially malicious traffic.

Detailed explanation-3: -A circuit-filtering firewall (also called a circuit-level gateway) works at the transport and session layers of the OSI model. It can examine the TCP handshake information that is sent between computers to verify that a session request is legitimate.

Detailed explanation-4: -Because TCP/IP is the de facto standard of communications protocols in today’s networks, most packet-filtering firewalls support at least this protocol. However, packet-filtering firewalls can support other protocols as well, including IPX, AppleTalk, DECnet, and Layer 2 MAC address and bridging information.

Detailed explanation-5: -A packet filtering firewall is a network security feature that controls the flow of incoming and outgoing network data. The firewall examines each packet, which comprises user data and control information, and tests them according to a set of pre-established rules.