Firewalls: Applications vs. Stateful
Firewalls sieve the traffic switched between networks, putting into effect each network’s access control policy. It defends an inside trusted network from being attacked by untrustworthy outside attackers. We have some two types of firewalls: packet filtering and stateful inspection firewall. In packet filtering, routers provide basic filtering at the network layer and packet filters. They are also known as access control list (ACL), and function on the values carried in each (TCP) transfer control protocol packet. The fields include protocol type, source and destination IP address, and origin/source and destination port. The stateful inspection firewall maintains a table of active TCP and (UDP) user datagram protocol sessions; such entries made record the session’s source and destination IP address, port numbers, and current TCP sequence numbers. Only entries that meet a certain security policy are permitted to pass through the firewall, while the rest that do not match the policy are denied access.
In general, stateful inspection is more secure than packet filtering since it only allows packets belonging to an allowed session. It only gives authorization to programs in traffic that belong to an existing and approved session. On the other hand, stateful inspection can validate the user when the session is recognized. It also determines and verifies whether the packets really carry HTTP and hence can filter URLs to restrict access to unauthorized sites. In packet filtering, in the case of large networks, they are not able to offer high-speed firewall protection due to the complexity that occurs from the large networks, hence resulting to reduced speed.
Commercial examples of stateful inspection firewall include Kaspersky Internet Security and Norton antivirus while packet filters include windows firewall and Check Point Software Technologies Fire Wall-1. I would go for kasperskey internet security because it is a stateful inspection firewall hence it is more effective. It is widely used and easily available in the markets hence convenient and even more secure.