Note: At the time of writing this is only applicable to Developer Preview 1 and 2
If you're trying to reach out from (or back in to) a Mac running OS X 10.10 Yosemite, Developer Preview, you may have found that your Bonjour networked machines aren't resolving.
This is because the mDNSResponder and mDNSResponderHelper are disabled (for some reason.) To re-enable them, you need to edit the com.apple.mDNSResponder.plist. You'll find it located at:
/System/Library/LaunchDaemons/com.apple.mDNSResponder.plistYou'll find a couple of lines near the top:
<key>Disabled</key>
<true/>Delete those lines, and save.
You'll need to reload and start mDNSResponder so in the terminal:
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist.local names should now resolve. (Remember to try just the machine name first, as .local sometimes doesn't resolve properly.)
To check the service is running, use:
ps aux | grep -i dnsYou should see /usr/sbin/mDNSResponder running, if not, try restarting the service as above.
after doing this (previews 5, 6 and 7), the permissions for com.apple.mDNSresponder are whacked. The OS is now throwing errors each time a network connection is NOT present:
This computer's local hostname "xxxx.local" is already in use on this network. The name has been changed to "xxxxx-%incrementing_number%.local".
Verifying and repairing permissions with diskutil doesn't resolve the issue. Nor does adding the lines back in. The error is repeatedly thrown until a network connection is obtained.
.local now resolves, but this is a pesky error for sure. Proceed with caution.