Question

A proxy firewall filters at _________

(a) Physical layer

(b) Data link layer

(c) Network layer

(d) Application layer

I got this question in class test.

Enquiry is from Firewalls topic in portion Network Layer of Computer Network

Answer 1

The correct answer is (d) Application layer

For explanation: The application firewall is typically built to control all network traffic on any layer up to the application layer. It is able to control applications or services specifically, unlike a stateful network firewall, which is – without additional software – unable to control network traffic regarding a specific application. There are two primary categories of application firewalls, network-based application firewalls and host-based application firewalls.