Which type of firewall combines packet-filtering with network address translation?

The type of firewall that combines packet-filtering with network address translation is stateful multilayer inspection firewalls. These firewalls operate at multiple layers of the OSI model, allowing them to inspect and track the state of active connections, making decisions based on both the packet headers and the overall state of the traffic.

In this context, packet-filtering is used to examine the headers of packets and determine whether to allow or block traffic based on predefined rules. Network address translation (NAT) is utilized to modify the source or destination addresses of packets as they pass through the firewall. This process not only enhances security by obscuring internal IP addresses from external entities but also optimizes the use of IP address space.

The functionality of stateful multilayer inspection firewalls allows them to be more effective in addressing complex security threats, as they can maintain context about established connections and apply filtering rules accordingly. This combination of packet-filtering and NAT provides both security and functionality for managing IP addresses and connections, which is crucial in many organizational environments.