Packet Filtering Firewalls: According to the OSI model, Layer 3 of the network layer is where packet filtering firewalls operate. To decide whether to accept or reject a packet, they look at its source and destination IP addresses, ports, and protocols. Although efficient, these firewalls aren’t able to inspect packet contents, which leaves them open to some attacks.
Stateful Inspection Firewalls: Stateful inspection firewalls, also refer to as dynamic packet-filtering firewalls, are able to track the status of network connections in addition to performing packet filtering. These firewalls make sure that only legitimate packets connect to those connections are permit through and keep track of all connections that have been made. Comparing stateful inspection to packet filtering alone, the security is improv.
Application-Level Firewalls (Proxy Firewalls): Proxy firewalls and application-level gateways both function at the OSI model’s seventh layer, or application layer. They serve as a bridge connecting the internal network and external systems. These firewalls examine network packet content and take action in accordance with the set-up application-specific rules. Proxy firewalls can cause latency because of the additional processing requir, despite the advanc security features they offer.
Next-Generation Firewalls (NGFWs): NGFWs are an advancement of traditional firewalls that include cutting-edge features beyond packet filtering and stateful inspection. NGFWs frequently come with features like application awareness, deep packet inspection, intrusion prevention, and integration with threat intelligence feeds. A more thorough defense against contemporary threats is offered by these strong firewalls.