In the example above, the difference is four milliseconds for a valid address versus five seconds for an invalid one.
This is surprising --- I'd expect a DNS lookup failure to be much faster than a default connection timeout which comes after a successful DNS lookup.
That said, I've always found the <name>s-mac-xxxx to be a bit of an odd choice, especially considering it's from a company that advertises privacy as a huge selling point; either they don't expect you to use your real name, or this is a case where "user friendliness" took precedence. From the privacy perspective, Windows' randomly generated hostnames would be better.
> This is surprising --- I'd expect a DNS lookup failure to be much faster than a default connection timeout which comes after a successful DNS lookup.
Unlike regular DNS where you're asking a single server at a single IP for a yes/no answer, mDNS is multicast, so no single server can authoritatively say no†. You can only detect that there are no records when the lookup times out because no servers have responded.
† Not technically true, a device can say no if it knows it owns that name.
The reason users' real names are in the hostnames is possibly because of AirDrop. The system appears to use the hostname for things like Personal Hotspot and AirDrop, and other types of names would probably lead to widespread confusion when it came time to share a file.
This is surprising --- I'd expect a DNS lookup failure to be much faster than a default connection timeout which comes after a successful DNS lookup.
That said, I've always found the <name>s-mac-xxxx to be a bit of an odd choice, especially considering it's from a company that advertises privacy as a huge selling point; either they don't expect you to use your real name, or this is a case where "user friendliness" took precedence. From the privacy perspective, Windows' randomly generated hostnames would be better.