Cm500 losing connection

Hi,

I've had my CM500 modem for what's probably coming close to two years now.  I've never had any issues with it, but for some reason, as of about two days ago, it's started disconnecting.  It will work fine, then suddenly there's just no internet.  The lights on the modem turn red and when I tried to troubleshoot it, all I'm getting is that an Ethernet cable is loose or disconnected.  I know that's not the case because the Ethernet cable is firmly connected.  I've even tried swapping the cable with another, turning it around, etc and get the same notification.  I've tried cycling the power, but that isn't solving the issue.  It happened again last night and went out close to 10pm.  It was still out at 1am, but was back on when I got up this morning.  Netgear's troubleshooting tips aren't helping, so hopefully someone among the community has some ideas?