When creating a new intrusion rule in a Cisco Secure Firewall Threat Defense (FTD) device, the keyword type "metadata" must be used to add a line that identifies the author of the rule and the date it was created. The metadata keyword is used to store additional information about the rule, such as authorship and creation date.

Steps:

In FMC, navigate toPolicies > Intrusion > Rules.

Create a new rule or edit an existing one.

Use the "metadata" keyword to add information about the author and date.

Example:

metadata: created_at 2023-06-15, author "John Doe";

By using the metadata keyword, you ensure that the rule contains relevant information for tracking its creation and authorship, which is essential for maintaining rule documentation and accountability.