What command would you use to view currently active Kerberos tickets?

The command to view currently active Kerberos tickets is 'klist'. This command displays the tickets that are currently held by the user, including information about the ticket’s expiration time, the principal for which the ticket was issued, and the ticket’s encryption type. It is particularly useful for verifying that you have a valid Kerberos ticket, which is necessary for authentication within a Kerberos-secured environment.

In contrast, other commands serve different purposes. 'kinit' is used to obtain new tickets and authenticate to the Kerberos server, but it does not display active tickets. 'kvno' retrieves the current version number for the specified principal’s key, which is not related to viewing active tickets. Lastly, 'kdestroy' is used to destroy active Kerberos tickets, effectively logging the user out of the Kerberos environment, rather than listing them. This distinction makes 'klist' the correct answer for viewing currently active tickets.