Made clear DNS subsystem is used

[samrueby]

Documentation was confusing because is worded as if it queried using the DNS protocol, not the subsystem. If it was just using the DNS protocol, it could be bypassing the hosts file, similar to the nslookup tool. Confirmed this code does not bypass the hosts file. See issue: dotnet/docs#8418 (comment)

Fixes dotnet/docs#8418

[karelz]

I think we should leave out "Because the DNS subsystem is used, entries in the hosts file will be returned."
That is Linux specific + I don't think it is necessary. Changing the DNS server to DNS subsystem is IMO fine.

[rpetrusha]

@davidsh, could you take a look, please?

[samrueby]

@karelz, Sorry, what do you mean "Linux specific". I'm only focusing on Windows, which also has a hosts file.

[karelz]

@samrueby ok, I didn't realize that. Either way, I don't think the last sentence is necessary or super-valuable IMO.

[samrueby]

@karelz Okay. Obviously I'm biased but I think it removes any question of how the host is resolved. Maybe it could be worded in a better way?

[karelz]

@samrueby I don't think it is about wording. Clarifying that it is about DNS subsystem vs. protocol makes sense to me.
Explaining into more details what the subsystem does is IMO not worth it, unless it confuses more people. Majority of people don't even care about DNS protocol vs. DNS subsystem differentiator IMO.
I don't feel super strong about it though. I'll be happily overruled by majority - if others think it should be there (or if there are more people with the same question), I won't push back.

[davidsh]

I think the change is ok, except this final sentence should not be added:

"Because the DNS subsystem is used, entries in the hosts file will be returned. "

I think that adds too much implementation detail to the documentation. These APIs do not actually call DNS directly. They call operating system "name resolver" APIs first. Then those operating system APIs will use various mechanisms including DNS protocol to resolve the name.

[samrueby]

Updated.