A firewall rule can be summarized as source, destination, service, and _____.

### Why this is right The action states what the firewall should do when traffic matches the rule, such as allow or deny. The other rule fields identify which traffic is being evaluated. ### The concept A basic rule answers four questions: who sent the traffic, where it is going, what service is requested, and what should happen. These correspond to source, destination, service, and action. Some firewalls can also use application and user information in their policies. ### Terms - **Security policy**: A set of rules that controls network traffic. - **Service**: The network function or protocol and port being requested. ### Remember A rule identifies traffic and then specifies an action.