Hello @josephm
First off all thank you for all your answer.
edit: plus, please next time add your yang in text format to allow easy copy for experiments and giving hints, image prevents this and makes users type it manually (if they have time))
definetly, you’re right, i want to be a quick, so that i clipped the image, but i’ll consider this, i’ll put text.
must ". < ../max-lease-time";
i tried this, but it couldn’t work. but i tried over netconf not CLI.
however, “must” statement didn’t work, then i tried “when” statement. I know that “when” is quite different from “must” statement.