My DNS server used to be the DNS server for a company's domain. However they moved elsewhere. Oddly enough, years later they were still listing my DNS server in their whois record (or, more properly, in their glue records).
Now I'm curious if there are other domains doing the same thing.
Is there a way I can find which domains list my server as their nameserver?
In the old days one could query for "host records" with whois but I don't see a way to do that now