[Interest] Any known issues with rDNS lookups on OS X?

[Bob Hood]

I'm using Qt 5.4.2 code to retrieve a connected machine's hostname (via 
QHostInfo::lookupHost()).  The code works perfectly under Windows, but fails 
under OS X.  I get the hostname under Windows, but I'm left with only the 
connections network address on OS X.

Does anybody know of any existing issues with reverse-DNS look-ups on OS X?