Overview of ACLs

An access control list (ACL) is used to filter traffic.

An ACL filters IP traffic using matching conditions and the permit or deny action.

An ACL consists of matching conditions and an action:

• Matching conditions: The FW supports multiple types of matching conditions, such as source addresses, destination addresses, transport-layer protocols (TCP or UDP), and application-layer protocols (such as HTTP and FTP).
• Actions: apply to matched traffic. Two actions are supported: permit and deny.
  

  An ACL must be referenced to take effect. The meanings of permit and deny defined in an ACL vary according to the features that reference the ACL.