What is a packet-filtering firewall?
A packet-filtering firewall controls access based on information in the packet header. As you may know, data that has to be transmitted across the network is broken down into small chunks called packets. Each packet has a header and a part of the original data, called its content. The header consists of information like the source, destination, port, and number of the packet in the sequence. How is a packet-filtering firewall different from an application-proxy firewall? An application-proxy firewall is implemented in proxy servers while a packet-filtering firewall is usually implemented in routers. An application-proxy firewall works on the application layer while a packet- filtering firewall works on the network layer. An application-proxy firewall can thus block application-specific data while a packet-filtering firewall cannot. An application-proxy firewall sits in-between the trusted and untrusted networks, and does not allow a direct connection between them. When access is grante
