You want to allow all of your company’s users to access the Internet without allowing other Web servers to collect the IP addresses of individual users.
What two solutions can you use? (Choose two).
A . Configure a proxy server to hide users’ local IP addresses.
B . Assign unique IP addresses to all users.
C . Assign the same IP address to all users.
D . Install a Web content filter to hide users’ local IP addresses.
E . Configure a firewall to use Port Address Translation.
In computer networks, a proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server and the proxy server evaluates the request as a way to simplify and control its complexity.
Proxies were invented to add structure and encapsulation to distributed systems. Today, most proxies are web proxies, facilitating access to content on the World Wide Web and providing anonymity.
Port Address Translation (PAT) is a subset of NAT, and it is still swapping out the source IP address as traffic goes through the NAT/PAT device, except with PAT everyone does not get their own unique translated address. Instead, the PAT device keeps track of individual sessions based on port numbers and other unique identifiers, and then forwards all packets using a single source IP address, which is shared. This is often referred to as NAT with overload; we are hiding multiple IP addresses on a single global address.
Source: Cisco Official Certification Guide, Port Address Translation, p.368