I agree about the first two. The legal one being the most strong.

WRT "state or province": I've modelled quite some GIS data and tend to follow abstractions laid by OSM here. Where "state" is very different from "province" because in many locales that is the case;

But maybe your model is purely Chinese and the OSM model -albeit being global- has a poor local fit.

The latter: nah. It's the one I know about most, and I'd say, depending on your use-case, "address", "host", "location", URI, URL, etc are a better name for what you are modeling than "DnsOrIpAddress". If only for the fact that this can be read as "DNS Address Or IP address" as well as "DNS, or IP-Address". It is truly a bad name in many situations.