Which command provides detailed information about a specific interface's operational state?

The command that provides detailed information about a specific interface's operational state is "show interfaces extensive." This command offers an in-depth view of the interface's status, including not only its operational state but also various other parameters such as the physical status, protocol status, error counts, and MTU settings. It is particularly useful for troubleshooting as it provides more comprehensive data than simpler commands.

While other commands like "show interfaces configuration" focus on the interface's configuration settings, or "show interfaces statistics" might present statistical data about traffic and errors, they do not provide the same level of detail regarding the operational state as the "show interfaces extensive" command does. The command "show interface detail," which is not standard in Junos but may be used in other contexts, might suggest it could fulfill a similar purpose. However, in Juniper's context, "show interfaces extensive" is the standard command for operational state details.