Proxy Servers

Correct Answer: Content filtering proxy

A content filtering proxy is the most appropriate for this task as it has the ability to block access to specific websites. This type of proxy server can be configured to restrict certain websites, making it useful for organizations like Company D who want to monitor their employees' internet activity. A forward proxy, on the other hand, only serves as a gateway to the internet and does not have filtering features. A reverse proxy is mainly used to load balance among several servers and does not block access to specific websites. Lastly, a transparent proxy, while can monitor internet activity, it does not typically block access to certain websites.

Correct Answer: Forward proxy

The best proxy type for Company A's needs would be a Forward proxy. Forward proxies are suitable for these situations because they can cache web content, thereby reducing the overall bandwidth consumption. A forward proxy sits between client computers and the internet, serving requests from clients seeking resources from other servers (in this case, internet resources). By caching these resources, the forward proxy reduces the amount of traffic that needs to cross the company's network, which can lead to substantial savings in bandwidth. On the other hand, Reverse proxy, Transparent proxy, and SOCKS proxy are not the best fit. Reverse proxy is used to distribute network load, Transparent proxy is used for content filtering and does not cache content, and SOCKS proxy is a generalized proxy protocol that does not inherently support caching.

Correct Answer: Reverse proxy

A 'Reverse proxy' is the best choice for Company B to address their web server security concerns. A reverse proxy helps handle inbound traffic from the internet and directs it to the appropriate server on the company's network. This adds a layer of security because the originating IP address of the traffic never directly interacts with the company's server. Instead, all traffic goes through the reverse proxy, which can offer features like SSL encryption, load balancing, and protection from DDoS attacks. Also, malicious or unwanted IP addresses can be easily blocked. 'Forward proxy', on the other hand, primarily helps with outbound traffic from a network to the internet, providing anonymity to the user but not necessarily enhancing the security of the server. 'Transparent proxy' does not hide the user's original IP address which means it cannot provide the necessary protection from malicious IPs for the company's server. Lastly, a 'SOCKS proxy' is more about routing specific types of traffic over different types of networks, and less about security. Although it could provide a layer of security, it would not be as efficient as a reverse proxy in this scenario.