CMMC Practice Requirement:

Monitor, control, and protect organizational communications (i.e., information transmitted or received by organizational information systems) at the external boundaries and key internal boundaries of the information systems.

CMMC Requirement Explanation:

The goal of this control is to protect your systems from network-based attacks using firewalls. To do this firewalls separate your company's networks from attackers. Firewalls also control the traffic allowed across your network. These two features prevent and limit the effectiveness of network-based attacks.

Example CMMC Implementation:

Deploy a firewall between your company network and the internet. Your internet router generally has a built-in firewall. Configure your firewall to only allow authorized traffic in and out of your network. Achieve this by blocking unnecessary/unused websites, services and ports. Unnecessary websites include adult, gambling, and malicious websites. If you have several internal networks, deploy a firewall between them. Only allow necessary traffic between your networks.


- Scenario 1:


Alice is a system administrator at a small company. She configures the firewall on her router to only allow HTTP and HTTPS traffic to exit her network. She also configures it to block gambling, pornographic, and malicious sites. Alice is now monitoring, controlling, and protecting her company's network communications.
<img src='https://cmmc.test/images/practices/175/firewall.png' class='img-fluid' alt='This diagram shows a firewall filtering traffic between a company's network and the internet.'>
This diagram shows a firewall filtering traffic between a company's network and the internet.

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