The router is built in to the Netgear C6300BD, and it wasn't happening to internal addresses, only external. Didn't matter if it was wired or wireless, or how many devices were connected to the router. dslreports smokeping test showed the issues only in California, and I'm with Cox San Diego.
It's been happening for the last week, but this morning it seems to be gone. I will reply if the problem appears again.