"Back to my Mac" giving DNS error

I having this problem more and more now. Screenshot attached.



Because of this issue, I am unable to do some of the stuff that relates to Handoff or Continuity, like:



1. Making and receiving phone calls on the Mac;

2. Messages. When I try to send a Message from the iMac, I get an error saying message cannot be sent.



Oddly enough, webpages opened on the iMac show up n the iPhone and vice versa.



I reset the PRAM, it worked briefly, and then today again it does not work.



If it helps, I shut down the iMac every night and turn it on every morning. Also, I am connected wirelessly through my airport Extreme, with all DNS stuff configured on the AEBS instead of on the Mac (since I have multiple Macs and iDevices).



Re. DNS, I have tried Google DNS, OpenDNS, and my ISP's DNS - al of them exhibit the same issue; again, intermittently.



Any ideas on what else I could try?



Thanks and cheers

Attached Images

iCloud Error.jpg (78.5 KB)

via ehMac.ca http://ift.tt/1ycVQ6r