14.8 Firewall

Question 1

Firewall

Answer 1

A device or software that inspects network traffic based on a set of rules.

Question 2

Intrusion detection system (IDS)

Answer 2

A feature that detects intrusion attempts and alerts the system administrator.

Question 3

Intrusion prevention system (IPS)

Answer 3

A feature that detects intrusions and takes actions to prevent it, including reporting, blocking, or dropping traffic when intrusions occur.

Question 4

Network appliances

Answer 4

Devices that exist on a network to provide certain services for that network.

Question 5

Circuit-layer Gateway:

Answer 5

This firewall checks the traffic moving through a network by looking at the connection itself, rather than the data being sent. It only cares if the connection between computers, like phone lines between two people talking, is real and valid. If the connection is good, it allows the communication to continue.

Question 6

Packet Filtering:

Answer 6

This type of firewall looks at every piece of information (called a packet) being sent over the network. It checks things like the “from” and “to” addresses, similar to how the post office checks the address on a letter. If the packet doesn’t match the allowed list of addresses (like a list of trusted addresses), the firewall stops it.

Question 7

Application-level Gateway:

Answer 7

This firewall looks deeper into the packet, like reading the contents of a letter to see what it’s about. It checks if the data inside the packet is meant for a specific app (such as a web browser or a game). If the firewall thinks the app shouldn’t use that data, it blocks it.

Question 8

Access Control List (ACL):

Answer 8

This is like a rulebook for the firewall. It’s not a firewall itself, but it’s a list of rules the firewall uses to decide which data packets can come in or go out. For example, the rules might say, “Only allow packets from trusted websites.