What is Stateful firewalls?

Stateful firewalls inspect network traffic and track the state of network connections. Unlike stateless firewalls that only examine packet headers, stateful firewalls analyze the entire connection, including source and destination IP addresses, ports, and sequence numbers, to determine if a packet is part of an established, legitimate session. This allows them to make more informed decisions about whether to allow or block traffic, providing better security against various attacks, such as spoofing and denial-of-service attacks. They are commonly used to protect networks by examining incoming and outgoing packets and blocking those that do not match known, valid connection states.