Explain the process of Application Layer Filtering
The incoming network packets propagate up a “hardened" stack until it reaches the highest protocol layer found in the packet.
The packets move out of the network stack to the application proxy listening on that port.
The Packet data and header information form the highest protocol layer.
The proxy service compares data against acceptable command rules defined in accept and deny lists. The proxy service may perform data modification, authentication, logging, URL filtering etc
Packets are either dropped or sent onto the host's port or a remote host.