I’ve been hacking a part of the w-e w/ my firewall setting (mainly cause my firewall blocks my wifi network ..). Everything is fine right now, but i’m wondering what is the difference in satefull and stateless firewalls.
Here is a quote from Sun:
When talking about protocols it is possible to describe TCP as stateful and UDP and IP as stateless. As such TCP will automatically retransmit lost or garbled data independent of the application, whereas an application using UDP will have to manage retransmissions itself.
When talking about firewalls and/or firewall functions in routers stateful and stateless are not necessarily related to specific protocols but more used to describe how firewall controls forwarding/passing of packets.
A “stateless” product looks at each packet and applies rules to each packet independent of the previous packets and determines whether to forward or drop the packet independent of the specific protocol, eg a stateless product will test source and destination addresses and port and ACK bit settings to determine whether to forward or drop the packet.
A “stateful” product also looks at each packet and applies rules, but the rules or tests applied to each packet may be modified depending on packets that have already been processed or in the case of an application relay it will maintain state by definition.