What happens to traffic not explicitly allowed by a firewall rule using Allow?

When a firewall rule is set to Allow, it explicitly permits certain traffic to pass through the firewall. Any traffic that does not meet the criteria defined by the Allow rules is generally subject to a default policy, which typically denies or drops that traffic. This mechanism ensures that only authorized and intended communications are permitted, enhancing the security posture of the network.

In practice, firewalls operate on a principle of least privilege, meaning that if traffic is not explicitly allowed, it is automatically blocked or dropped. This reduces the risk of unauthorized access and helps safeguard the integrity of the network by preventing unwanted or potentially harmful traffic from penetrating the security boundary.

Logging, warnings, or quarantining actions would be more specific functions that can be configured separately, but they are not the default behavior for traffic not explicitly permitted by an Allow rule. Therefore, dropping the unallowed traffic is the most accurate characterization of how a firewall handles such cases.