Hack the Route Start free Open app Firewalls
Firewall types
From packet filters to next-generation firewalls: how much of the traffic each kind understands.
A packet filter looks at each packet's addresses and ports alone. A stateful firewall also remembers connections. A circuit-level gateway (SOCKS) relays whole TCP connections: it checks who may open a connection to where, then copies bytes without understanding them. An application proxy speaks the protocol itself, so it can judge a URL or a command; a web application firewall is one in front of web servers, matching requests against rules. A next-generation firewall puts these together in one box: stateful filtering, knowing which application a flow belongs to whatever its port, intrusion prevention, and rules by user rather than address.