How does a Stateful Firewall enhance security compared to a Packet-Filtering Firewall?

A Stateful Firewall enhances security by tracking the state of each connection, which is key to its functionality. Unlike a simple Packet-Filtering Firewall that makes decisions based only on predefined rules related to packet headers, a Stateful Firewall maintains a state table that records the status of active connections. This allows it to determine whether an incoming or outgoing packet is part of an established connection or if it is an unsolicited request.

By understanding the state of traffic and recognizing the context of communication, stateful firewalls can make more informed decisions about which packets to allow through. This capability prevents certain types of attacks, such as spoofing, since the firewall can assess whether a packet corresponds to a legitimate and previously established session. Furthermore, this awareness of state helps in managing and enforcing security policies that vary based on the nature of the ongoing communication, enhancing overall security significantly.