Final answer:
A firewall rule that rejects or drops traffic is usually represented by a prohibition icon, like a red circle with a diagonal line, or one that implies a 'stop' or 'block' action.
Step-by-step explanation:
In the context of firewall configuration, a rule that rejects or drops traffic is usually indicated by an icon symbolizing a prohibition, such as a red circle with a diagonal line through it, or perhaps a hand signifying 'stop'. When configuring firewall rules, the icons differ depending on the software or hardware being used. However, most firewall interfaces aim to provide a visual cue to make it easy to understand the action that a rule will perform. If it is a 'reject' rule, it may illustrate an arrow bouncing off a wall, while a 'drop' rule might show an icon that suggests blocking or removing something, often similar to a trash can or a cross.
Differentiating between 'reject' and 'drop': 'Reject' means that the firewall sends back a response to the source informing that the packet has been rejected, while 'drop' means that the packet is silently discarded with no response sent. This is an essential aspect of creating user rules in a firewall to ensure network security.