DoS Attacks causing connection issues

I've been having connectivity issues for months now. The internet typically goes down 5-10 times a day (probably more). I've been on the phone with Netgear techs 3-4 times. They always give different advice, but nothing works. Most recently, the tech told me that everything with the router/modem settings looked fine but that Comcast needed to do MAC provisioning. I called up Comcast again and they said it was provisioned. By the way, I've had Comcast techs come out twice in the last six months and they saw nothing awry on their end. Looking at the logs, I see lots of DoS attacks, both port scans and ICMP floods. Any help would be appreciated.