Which command displays all signed certificates on the Puppet master?

The command that displays all signed certificates on the Puppet master is "puppet cert list -a." This command is specifically designed to list all certificates that have been signed by the Puppet Certificate Authority (CA). The "-a" flag represents "all," which means it includes both active and inactive certificates in the output.

Using this command ensures that administrators have a comprehensive view of all signed certificates, which is crucial for managing nodes effectively in a Puppet environment. The ability to see these certificates allows for tasks such as auditing, troubleshooting, and verifying the identity of nodes that are trusted by the Puppet master.

In contrast, other commands either do not accurately convey the intended task or do not exist. For instance, commands that might initially seem relevant but serve different purposes, like "puppet cert show -a" or "puppet cert lst --all," either incorrectly specify the command or use nonexistent flags. Thus, "puppet cert list -a" is the correct choice for this operation.