I assume you don't know of any way to use some kind of auto configured addresses on the interfaces though in the world of IPv4, and you still have to manage and allocate address space for the real physical interfaces for routers to route by.Yes, this is quite common in IPv4 space as well, called a Loopback address. For nice traceroutes, I actually set pref-source on all routes to the loopback address too so you dont have to name / PTR and catalog all the interface addresses.