OS X 10.10 Yosemite DNS and Bonjour not working? Here is a fix!

Ever since I upgraded from the Yosemite Beta to the final release, certain things have not been working.  In particular, I could not browse to any network printers, NAS devices, or even see my Aiport Extreme from the Airport Utility.  My wifi and internet were working, just nothing on my local network.  I knew something was up with Bonjour, and by extension, my internal DNS (discoveryd service, new for 10.10 Yosemite) for my particular machine.

After 2 days of frustration, I’m happy to report that I fixed this.  Here’s how:

Launch the ‘Console’ app, and look in the logs and hopefully you’ll see many entries for variations of this error:

discoveryd Basic DNSResolver  dropping message because it doesn’t match the one sent

specifically (for my machine in this moment of time):

11/4/14 12:54:06.002 AM discoveryd[2158]: Basic DNSResolver  dropping message because it doesn’t match the one sent Port:0 MsgID:0

After much searching on the internet, and many plist deletions, etc. nothing worked.  So then I tried this:

System Preferences -> Network

At the top of that preference pane, there is a ‘Location‘ dropdown.  It was set to ‘automatic‘.  I clicked on that, and created a new location called ‘Home‘ (you can call it whatever you want, really).  Then my wifi connection reset itself, and EVERYTHING started working again.

Creating a new network location must have fixed some errant config file somewhere that was causing DNS and/or Bonjour lookups on my internal network to fail.  All is good now.

I can now browse for all bonjour devices, see my airport extreme, etc.  Everything works.  How lame and frustrating is that???

I hope this helps somebody!