How to whitelist for dashboard/admin area

I am using ConcreteCMS 8.5.x and want to whitelist a certain number of IP addresses to be able to login into the dashboard. Is this something that is already available in the core? I do see black/white lists - yet the IP addresses I put in the whitelist are just randoms and I can still login. So I am assuming this is not how it works for whitelisting, so what does this do?

Putting IP addresses in that list is just a way to ensure they won’t ever get banned for instance if you get your password wrong 3 times

I have not tried this. If the blacklist supports patterns or ranges, you could approach the problem the other way round and blacklist a sufficiently big range of IP that only your desired IP remains.