Stateless and Stateful Firewalls are 2 commonly referred Firewall types. While Stateless Firewall works by treating each packet as an isolated unit, Stateful firewalls works by maintaining context about active sessions and use “state information” to speed packet processing. Infact Stateful Firewalls use the concept of state table where it Stores the state of legitimate connections. Stateless Firewall filters based on header information in packet like Source IP, Destination IP, port number etc. On the contrary, Stateful Firewalls filter packets by matching to valid states in the state table.
Some of benefits that can be reaped from Stateless Firewalls include faster performance and low memory utilization. Stateful Firewalls benefits include higher security and performing application layer filtering to a certain level.
The differences between both Stateless and Stateful Firewalls is detailed in below table –