Hello! Just found this thread.
I'm running the latest build of the Yosemite public beta and I've been encountering significant Wi-Fi issues on my MacBook Pro after waking from sleep.
Internet access is unavailable for several minutes and seemingly non-existent during Power Nap. However, access to the web-based control panel of my router and any web site through its IP address is fineso I'm putting this down to some sort of DNS issue.
My router uses Google DNS and my devices use my router's DNS settings, not their own. Only my Mac is having connectivity issues. Similarly, my router is able to ping Google.com, however my Mac is notit must be the IP address of Google.com. Again, after several minutes, everything starts magically working again. Nothing out of the ordinary appears to be lurking in Console, so I'm really confused as to what the problem is.
Any idea what might be going on? Thanks!
Update to the stable 10.10.3 then get back to us