Network Architecture

Correct Answer: A VPN is a virtual private network that allows users to securely access a private network from outside the network's physical location.

A VPN, or Virtual Private Network, is indeed a method that allows users to securely access a private network from outside the network's physical location. It achieves this by creating an encrypted 'tunnel' between the user's device and the private network, thereby protecting data integrity and preventing unauthorized access. In contrast, the second answer is incorrect because a VPN is not a protocol used to manage network traffic and prevent congestion. It may utilize certain protocols like IPsec or OpenVPN but its primary function is for securing internet connection, not managing traffic or congestion. The third answer is wrong as well because though a VPN could use multiple servers to improve performance, it is not primarily a type of network architecture that uses redundant connections to improve network performance. Its primary function again is security and privacy, not performance enhancement Lastly, the fourth answer is partially correct that a VPN blocks unauthorized access to a network but it's incomplete as the primary function of VPN is not just to block unauthorized access but to provide a secure and encrypted connection over the internet.

Correct Answer: Printer

A firewall is a network security system that controls and monitors incoming and outgoing network traffic based on predetermined security rules. 'Printer' is not a typical component of a firewall. The other options such as 'Packet filter', 'Stateful inspection', and 'Application layer gateway' are all components or functionalities of a typical firewall system. A 'Packet filter' is a firewall technique used to control network access by monitoring outgoing and incoming packets and allowing them to pass or halt based on the source and destination addresses, protocols, or ports. 'Stateful inspection', also known as dynamic packet filtering, is a firewall technology that monitors the state of active connections and uses this information to determine which network packets to allow through the firewall. On the other hand, 'Application layer gateway' provides security components that augment a firewall by handling application layer protocol packets.

Correct Answer: To act as an intermediary between clients and servers

The primary function of a proxy server is to act as an intermediary between clients and servers. It stands between clients seeking resources and servers providing those resources. Through this role, a proxy server can provide additional functionality such as caching and security by preventing direct connections from outside the network. The other answers describe functions that are not specific to a proxy server: encryption during transmission is a general security principle that applies to various devices or protocols, not only proxy servers. Similarly, authenticating users attempting to access the network is typically handled by routers, firewalls, or server OS and not specifically by proxy servers. Lastly, routing traffic between networks is a function associated with routers, not proxy servers.