What is the best discovery scan option for a network environment where ping is disabled on devices?

In a network environment where devices do not respond to ping, the smart scan option is the most effective choice. This is because a smart scan utilizes various methods to discover devices on the network beyond just ICMP echo requests (which is what ping uses). It can leverage protocols such as ARP, SNMP, or other network-based discovery mechanisms to identify devices.

Unlike a range scan that systematically attempts to ping a range of IP addresses, or a CMDB scan that relies on an existing Configuration Management Database to identify devices, the smart scan is designed to adapt to conditions where traditional discovery methods fail. It can collect more comprehensive information about network devices based on available network protocols, making it suitable for environments where ping responses are not an option.

The L2 scan focuses on Layer 2 frames and can reveal devices that are directly connected within the same broadcast domain. However, without ping responses, the smart scan's broader approach using various protocols gives it an advantage in discovering devices across more complex networks. Thus, the smart scan is the most appropriate choice for effectively identifying devices in an environment with disabled ping responses.