Having browsed through half the Internet without finding any decent documentation on how to do this, I gave up on Google and put together something myself. Hopefully it can be useful for other networking students.
I’m doing a lab for Cisco CCNP ROUTE where you’re supposed to set up OSPF over a Frame Relay (NBMA) hub-and-spoke topology with a headquarter and two remote sites. All subinterfaces must be configured as point-to-point. This is how you configure the Frame Relay part.