Network Defense Essentials (NDE) Practice Exam

Which type of firewall inspects traffic at the application layer ensuring specific criteria are met?

1. Stateful packet inspection firewall

2. Application firewall

3. Circuit-level gateway

4. Next-generation firewall

The correct answer is: Application firewall

The type of firewall that inspects traffic at the application layer is the application firewall. This type of firewall is designed to specifically analyze and filter traffic based on the specific protocols and data being sent, rather than just looking at the packet headers as traditional firewalls do. By operating at the application layer, an application firewall can enforce detailed security policies that consider the context within the application layer protocols, such as HTTP, FTP, or DNS. This level of inspection allows the application firewall to ensure that only legitimate data and requests are allowed through, blocking potentially harmful content and information that does not meet the established security criteria. This capability makes application firewalls particularly effective against threats such as web application attacks, where malicious actors target vulnerabilities in the application itself rather than the underlying network infrastructure. In contrast, the other types of firewalls mentioned focus on different layers or methods of traffic analysis. Stateful packet inspection firewalls track the state of active connections and make decisions based on the state and context of those connections, but they do not deeply inspect the application data. Circuit-level gateways operate at the session layer, monitoring the TCP handshake and maintaining sessions without inspecting the payload of the packets. Next-generation firewalls incorporate features from traditional firewalls but often extend to intrusion prevention and threat