my mac stopped loading most websites although they load on other computers
All of a sudden this morning I'm having trouble getting websites to open. I'm on an iMac. Everything was fine when I first got on the computer this morning. Then, it stopped being able to load most websites. I've tried using Google Chrome and Safari, and both have a problem. I have an ASUS notebook on the same network and I'm able to open sites just fine. The strange thing is on the iMac sometimes a website will open, but then when I try again it won't. It does open up my Gmail and Google Calendar consistently, but everything else mostly won't work. Can anyone tell me what's going on and how to fix this?
iMac (21.5-inch Late 2009), iOS 8.4.1, Bootcamp version 5.1.4 (500)