When configuring MST instances, what is the first step one should take?

When configuring Multiple Spanning Tree (MST) instances, entering the configuration terminal is indeed the first step one should take. This command mode serves as the starting point for making any configuration changes on a Cisco device.

Once you are in the configuration terminal mode, you have the ability to enter various configuration commands specific to MST. This includes specifying the MST region name, mapping VLANs to instances, and enabling MST on the appropriate interfaces, among other tasks necessary for the configuration process. It essentially provides the necessary context and environment for all subsequent MST configuration commands to be applied effectively.

Beginning configuration directly in the terminal is crucial, as no changes can be made outside of this mode. It ensures that the device is ready to accept commands and that any adjustments will be applied properly to the device's running configuration. This foundational step is indispensable in the configuration workflow, highlighting its importance in the process before any other actions can be taken.