Differences between Packet Firewall, Stateful Firewall and Application Firewall

1.Packet Filtering Firewall: The Packet Filtering Firewall is one of the most basic firewalls. The first step in protecting internal users from the external network threats is to implement this type of security. The first ever firewalls used were of packet filtering type only. As the trends of network threats started changing, so did the firewall building strategies. Most of the routers have packet filtering built-in, but the problem with the routers is that, they are difficult to configure and don’t provide extensive logs of the incidents.

2.State-full Firewall: A state-full firewall keeps track of the state of network connections (such as TCP streams or UDP communication) and is able to hold significant attributes of each connection in memory. These attributes are collectively known as the state of the connection, and may include such details as the IP addresses and ports involved in the connection and the sequence numbers of the packets traversing the connection. State-full inspection monitors incoming and outgoing packets over time, as well as the state of the connection, and stores the data in dynamic state tables. This cumulative data is evaluated, so that filtering decisions would not only be based on administrator-defined rules, but also on context that has been built by previous connections as well as previous packets belonging to the same connection.

3.Web Application Firewall (WAF): A WAF is to be implemented to a web server running which is hosting any type of website or web application. A web application firewall (WAF) is an appliance, server plugin, or filter that applies a set of rules to an HTTP conversation. Generally, these rules cover common attacks such as cross-site scripting (XSS) and SQL injection. By customizing the rules to your application, many attacks can be identified and blocked.

Hope this helps.