Which firewall type is often implemented when masquerading is enabled for local systems on external networks?

The correct choice is based on the concept of "masquerading," which is a form of network address translation (NAT) commonly used in firewalls to facilitate outgoing connections from a private network while concealing the internal IP addresses from external networks. When masquerading is in place, internal hosts can communicate with external networks as if they are a single entity, usually represented by the public IP address of the firewall itself.

An external firewall is specifically designed to manage traffic between an internal network (such as a private LAN) and the outside world (like the internet). It helps ensure that only permitted traffic is allowed to pass, protecting internal systems from unwanted access while enabling outgoing connections. The use of masquerading in this context allows multiple devices on the internal network to access the internet without exposing their individual IP addresses, thus providing both security and functionality.

In contrast, a public firewall usually refers to firewalls deployed in a public environment that may not provide the same internal protections, while DMZ firewalls are generally utilized to host publicly accessible servers in a segmented network area separate from the internal network. A work firewall often implies a more localized firewall for individual systems rather than managing a broader network traffic flow. Therefore, the external firewall best represents the scenario described,