Q: Safari Can't Find the Server

I keep getting the message "Safari Can't Find the Server" randomly for 10 minutes at a time.  Everything works fine, then once I get this message it tends to reoccur lots and internet access becomes very sporadic.

Connection is perfect it just will not load web pages.  Have restarted everything, emptied caches, etc and am at a loss.  Followed instructions from some old posts but they dont work and may be outdated I assume.

I have an iMac (24-inch, Early 2008) running OSX El Capitan 10.11.1

Has been occuring for 2 weeks now and I'm ready to throw my computer - cannot get anything done without interruptions.  Last 6 hours work should have taken 1-2 and its taken 30 minutes just to get this posted  :-/

Please help !!!!