What type of packet filtering does a firewall perform when it pays no attention to whether a packet is part of an existing stream of traffic?

The type of packet filtering that a firewall performs when it disregards whether a packet is part of an existing stream of traffic is referred to as stateless filtering. In this method, the firewall analyzes each individual packet independently without considering the context of established sessions or connections.

Stateless firewalls focus on the header information of each packet and assess it against predefined rules. This means they do not maintain a state table of active connections, which allows them to make decisions based solely on the rules defined for incoming and outgoing packets. They can be faster because they do not need to track ongoing connections, but they might be less effective at preventing some types of attacks that can exploit connection states.

In contrast, stateful packet filtering keeps track of the state of active connections and uses this information to determine whether a packet is part of an established connection or a new attempt. This allows for a more nuanced understanding of the traffic flow and improves security against various types of attacks that might try to exploit the connection state. Options like full inspection and deep packet inspection involve more comprehensive examination of packets and their payloads, focusing on the content rather than just the headers, which further distinguishes them from stateless filtering.