Very strange problem here, though it seems resolved now. But I'm curious as to the cause. I changed to Verizon FIOS for internet several months ago. On weekends, I would lose connection several (4-6) times daily. [weekdays are hard to judge since I don't use the computer much.] The connection came back when I rebooted the computer or the modem and router. The strange part is that I didn't lose my internet connection with my iPad or iPhone. [I made sure cellular was turned off and they were both in WiFi mode only.] Verizon insisted it was an Apple problem simply based on not having problems with any other device. And that seemed to make sense. So, I spoke with a senior Apple tech. We tested everything conceivable and could find nothing wrong with the iMac. Then he checked his database and found 2 almost identical issues, though Verizon was not the provider in either case. In one case, a firmware update for the router solved the problem. In the other, a replacement of the modem or router solved the problem. Reluctantly, Verizon sent a replacement router. It went down once a short time after. However, that was about 5 days ago and I haven't had an issue since. Has anyone encountered anything like this before? I'll also say that Verizon support is the absolute pits and I have no confidence in them whereas the Apple guy was quite thorough and unbiased, not to mention helpful.