Generally speaking, does failing to ping the DNS suggest the ISP is at fault?

I have been experiencing very random internet connectivity issues. when my internet connection suddenly fails, I can ping successfully 127.0.0.1, my PC's IP address, my routers address, my static IP address as igned to me by my provider, but I CAN NOT, however, ping my provider's DNS address. To rephrase: I CAN ping the ISP's DNS normally. During an outage I can not. Does this mean my ISP is to blame, generally speaking?