Cannot resolve .local hostname after upgrading to macOS Sierra

Turning on sharing may have worked at some point, but as of now this solution doesn't work any more [using Sierra].

Putting somehost.local in /etc/hosts fixed this particular issue for me, but in 2016 people shouldn't have to do this, especially if the host is resolvable via nslookup.

> Running "host mymac.local" gives Host server.local not found: 3(NXDOMAIN).

Which is normal 🙂

> pinging the hostname gives "Unknown host".

Which is not normal 😟

As Bonjour's Multicast Domain Name Service (mDNS) uses the ".local" suffix to identify Bonjour-accessible devices, are these two daemons running on your system:

1. /usr/sbin/mDNSResponder; and

2. /usr/sbin/mDNSResponderHelper

If not, which is very odd, then you need to manually restart them.

Open an Applications > Utilities > Terminal window and post the following command:

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

mDNS will then be running again, and should also reload and run the next time your boot without further intervention.

Hello piorange,

Use something other than ".local". That is a private domain run by the operating system. I don't know how you managed to keep it running this long. Pretty much every OS update comes with people complaining that their custom ".local" names aren't working.

mymac.local indicates that he has only being using the Bonjour service for a Mac on the network (possibly just his own) which is perfectly legitimate (see e.g. OS X Yosemite: Find your computer’s name and address) and it should be pingable. Of course, .local should not be used as a domain for normal DNS queries, but that's not what he is doing.

Is mDSNResponder running? What's the output of the Terminal command:

ps -ax | fgrep -i mdns

piorange did say "hostnames", suggesting more than one, and has been mucking around with Apache files.

Hello again piorange,

But the question is whether you have added your own .local host names using the /etc/hosts file. That is always going to be a problem. Try some other suffix and see if it works.

Hello again piorange,

Thanks for the clarification. You can ignore my previous replies.

Try to change your host name in System Preferences > Sharing. If that works, try to change it back.

I had the same issue and found out how to fix it: turn any of the sharing services ON in the system preferences.

(File sharing worked for me).

For some reason .local hostname is kept turned off unless any of the sharing services is active.

If you turn the sharing service off, the .local address will keep working for a minute or so and then get deactivated.