When a private network is connected to public ones, traffic between the private and public zones needs to be subject to rules. This filtering role is performed by a firewall. Firewalls apply access controls to ensure authorized use of the network. They perform a filtering function to analyze the properties of connection requests and then allow, deny, and/or log them as appropriate. While you may not be installing and configuring these devices at this stage in your career, it is important that you understand their use on the network edge.
As you study this lesson, answer the following questions: