Ask HN: Use after license expiration protection schemes

What are some good solutions to prevent businesses from using your software past termination of a licensing agreement or past a trial date?

Specifically, this is in the context of software that is installed on linux servers for which a monthly licensing fee needs to be paid.

Some ideas I had myself: - reduce reliability of software past certain date - use a licensing server with the software connecting to it to check if it is allowed to run - keep some type of secure date or time counter which is checked

Curious what scenarios you've had yourself in your startup dealing with customers and how you've handled this.