What type of firewall is needed to block unsolicited incoming traffic while allowing internal servers to access the Internet?

A stateful firewall is designed to monitor the state of active connections and determine which packets to allow through based on established rules and the context of the traffic flow. It keeps track of the state of connections (such as TCP streams) and makes decisions based on the state of the traffic.

In the scenario presented, where the goal is to block unsolicited incoming traffic while allowing internal servers to access the internet, a stateful firewall is ideal. It can distinguish between legitimate outgoing requests from internal servers and unsolicited requests from external sources. By maintaining a state table, it allows responses to be accepted back in only if there was an established outbound request, thereby ensuring that unsolicited traffic is blocked.

Other types of firewalls serve specific functions that may not align perfectly with the needs of this situation. For instance, a static firewall relies on a fixed set of rules and does not track the state of connections, which may lead to unwanted exposure or blocking legitimate traffic. An application firewall operates at the application layer and is focused on filtering specific types of content, which may be overkill for simply managing unsolicited incoming packets. A next-generation firewall incorporates advanced features such as intrusion prevention and deep packet inspection, which are beneficial for more complex environments but may not be necessary for the straightforward