Final answer:
The firewall rule action that denies all other traffic unless expressly allowed is typically referenced as 'deny by default' or 'implicit deny,' but none of the given options correctly describe this rule. A 'deny by default' rule is a standard security measure in firewalls, ensuring only permitted traffic is allowed.
Step-by-step explanation:
The firewall rule action that implicitly denies all other traffic unless explicitly allowed is known as a 'deny by default' or 'implicit deny' rule. In the context of the provided options, the correct answer is not listed in the given choices because these terms are more commonly associated with firewall configurations.
However, if one had to choose from the provided options, none would technically be correct as they do not fit the standard terminologies used in cybersecurity. But the concept closest to the principle of 'deny by default' or 'implicit deny' is not listed among the choices.
Firewall rules work by setting policies that control network traffic. The 'deny by default' rule is a security measure where a firewall blocks all traffic that does not match any of the previously defined 'allow' rules. This ensures that only traffic that has been specifically permitted by the network administrator can access the network.