Which utility would best help diagnose NAS mount points?

The most effective utility for diagnosing NAS mount points among the options is nfsstat. This utility provides valuable insights into the status of NFS (Network File System) mounts and can help troubleshoot issues related to file system performance and communication with the NAS device.

When it comes to analyzing NAS mount points specifically, nfsstat is tailored for this purpose, as it offers statistics about NFS operations, such as the number of calls, retransmissions, and errors. It is fundamental for diagnosing problems connected to file sharing and data retrieval from a NAS, making it the ideal tool for this scenario.

The other options focus on different functionalities. For instance, route is primarily used for viewing and manipulating the routing table of a network, ping checks connectivity to a specific IP address or hostname but doesn't give information about mounted file systems, and ifconfig is utilized to configure and display network interface parameters but lacks the specific context needed for diagnosing NAS mount points. Therefore, nfsstat stands out as the best choice for this particular task.